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International Journal of Advanced Structures and Geotechnical Engineering

Journal Papers (40) Details Call for Paper Manuscript submission Publication Ethics Contact Authors' Guide Line
1 Effects of Fibrillated Polypropylene Fibers on Plain Cement Concrete Composites, Vikrant S. Vairagade, Kavita S. Kene
Critical investigation for M-20 grade of concrete to study the compressive strength, flexural strength and tensile strength of fibrillated polypropylene fiber reinforced concrete (PFRC) containing fibers of 0%, 0.25% and 0.4% volume fraction of fibrillated polypropylene fibers of 15mm, 20mm and 24mm length were used. For compression test, the cube (15cmx15cmx15cm) and Cylinders (10cm diameter and 20cm length) were used. For splitting Test, Cylinders (10 cm diameter and 20 cm length) were used. A result data obtained has been analyzed and compared with a control specimen (0% fiber). A result data also compared between three different fibers strength. A relationship between Compressive strength vs. days, and tensile strength vs. days represented graphically. Result data clearly shows percentage increase in7 and 28 days Compressive strength and Tensile strength for M-20 Grade of Concrete.
2 Strengthening of Brick Masonry Walls Against Earthquake Loading, Khan Shahzada, Muhammad Javed, Bashir Alam, Mansoor Khan, Zaigham Ali, Hassan Khan, Syed Shahan Ali Shah
This paper presents a research on the enhancement of unconfined and unreinforced brick masonry walls against earthquake loadings in Pakistan. Different unreinforced brick masonry walls have been examined for compressive strength before and after retrofitting. In this research Ferro-cementing has been used for the strength improvement of unreinforced brick masonry. The impact of plaster on the durability of walls has also been regarded. The research of trial outcomes generate, that appropriate retrofitting can reduce the problems occurring due to future earthquakes. Retrofitting improved not only the overall strength of unreinforced brick masonry walls by 40 % and also enhanced its ductility.
3 Sulphate Attack in High-Performance Concrete - A Review, Bashir Alam, Muhammad Ashraf, Khan Shahzada, Salman Afzal, Kaffayatullah Khan
This study presents a critical review of the on-going techniques and strategies associated with the mitigation of Sulphate Attack in High-Performance Concrete structures. The materials and methods used for controlling and detecting degradation due to Sulphate attack are presented with a state-of-the-art discussion of their relative merits and demerits. The expansive reactions that lead to the appearance of cracks, its propagation and deleterious effects on concrete members are presented.
4 Autogenous Shrinkage in High-Performance Concrete - A Review, Salman Afzal, Khan Shahzada, Muhammad Ashraf, Bashir Alam, Kaffayatullah Khan
This study has been performed to evaluate the potential merits and demerits of mitigation-strategies of Autogenous Shrinkage of High-Performance Concrete. The experimental evaluation of autogenous shrinkage strain and the limitations posed by the experimental setup are of prime importance to review. The different experimental techniques and materials proposed by researchers are critically evaluated and a synopsis is presented.
5 Cost Optimization of Combined Footings Using Modified Complex Method of Box, Muhammad Rizwan, Bashir Alam, Faisal ur Rehman, Noreema Masud, Khan Shahzada, Tabinda Masud
This work aims at developing a direct-search computational procedure based on the Complex Method of Box with appropriate changes for obtaining optimal design of reinforced concrete combined footings. The objective function includes cost of excavation, filling, concrete and reinforcement for the footings which is minimized during the optimization process. The design variables comprise the depth, width and length of the footings; and the area of flexural reinforcement at the moment critical sections. The explicit constraints such as restrictions on dimensions of the footings and the implicit constraints such as the restrictions on stresses and displacements as per the relevant provisions of American Concrete Institute (ACI) specifications and codes, based on strength design method are satisfied. The Computer program is developed using Visual Basics .NET (VB.Net) programming language to perform the structural analysis, design and optimization of the combined footings. The method finds the optimum solution in terms of discrete variables. Two numerical examples are solved to observe the behavior of the optimization method. The results illustrate favorable design improvements and rate of convergence.
6 Study on Performance Evaluation of Adhesive Used for Cracks Injection in Concrete, Anwar Shah, Qaisar Ali, Bashir Alam, Khan Shahzada, Arsalan Khan
The aim of this experimental work is to determine and investigate the cost effective and user friendly methods of repair with the application of synthetic epoxies and cement grout by injection in cracked concrete. For the performance evaluation of the epoxies used for cracks injection, three beams of appropriate dimensions were cast. After proper curing and hardening, each beam was loaded to a point where appreciable cracks, four to five moderate cracks having 3mm to 4mm width, running 3/4th of the depth of beam, appeared and was taken as a standard for comparison. The cracks were then sealed and filled with epoxies by pressure injection using chemicals of the two manufacturers and cement grout. The beams were again loaded till the cracks like the previous ones appeared and then each beam was loaded to its full capacity. The design load carrying capacities of the beams were also calculated for the purpose of comparison with the loads at which appreciable cracks developed before and after injection and with the full load carrying capacities of the beams. The results of the tests carried out on epoxies for crack injection indicated that epoxies for injection, are effective and the load carrying capacity can be completely or partially restored in case of minor to moderate damaged beams. For restoring the strength of minor to moderate damaged beams the use of grout is recommended because of its lesser cost as compared to epoxies.
7 Conceptualization of role of shearing stress in understanding Earthquake mechanism, Umesh Prasad Verma, P. Hollis Watts, Amitabh Sharma
Approximately at 1000km depth in Mantle, enhanced thermal energy (probably generated due to influence of gravitational force associated with astrophysical sources) leads to shearing stress1. The maximum shearing stress outbreaks into two possible (at least) components: tangential and radial.2 The tangential always exceeds the radial at least by 120 Mpa. Such an enhancement results in propagation of sufficient amount of seismic energy, through the overlying stratum, away from the initiation point of shearing stress. The combined influence of internal friction (Columbian friction ?)3of overlying stratum, temporal extra-terrestrial gravitational pull (viz. by moon)4 and acceptable creep rate of straining stratum5 ,stress components exhibit a drop .From such an activity it is probably possible to detect the nature of tangential and radial components` additive or subtractive effects6 on magnitude and location of a seismic activity. We advocate that knowledge of such an inter relationship between earth system processes would help in better understanding of the genesis of intraplate seismicity and landslides activity [as in Brazilian landslide-14thJan11].A comprehensive study on this inter relationship between various processes may probably bridge gaps in our understanding of earthquake resultant activities and lead to area specific medium level forecasting, a positive development from the point of earthquake prediction.
8 Study on the Geotechnical Properties of Cement based Composite Fine-grained Soil, Grytan Sarkar, Md. Rafiqul Islam, Muhammed Alamgir, Md. Rokonuzzaman
This study investigates the effect of cement on the performance of soil, collected from Khanjahan Ali Hall at Khulna University of Engineering & Technology (KUET) in Khulna, Bangladesh. The addition of cement was found to improve the engineering properties of available soil in stabilized forms specifically strength, workability, and compaction and compressibility characteristics. Therefore, laboratory tests such as compaction, Atterberg limits, unconfined compressive strength, direct shear and consolidation tests for different percentages of cement content and original soil samples were performed. These test results show that the soil can be made lighter which leads to decrease in dry density and increase in moisture content and reduced compressibility due to the addition of cement with the soil. Besides that the unconfined compressive strength and shear strength of soil can be optimized with the addition of 7.5% of cement content.
9 Retrofitting of brick masonry columns by ferocementing, Khan Shahzada, Bashir Alam, Muhammad Javed, Zaigham Ali, Hasan Khan, Syed Shahan Ali Shah
This project has been selected in the aftermath of devastation in the North Pakistan and Kashmir due to damaging Earthquake of October 8, 2005. Retrofitting of masonry columns has been made by using ferrocement. Two sizes of columns have been used. 9 in x 9 in Retrofitted columns gave strength 1.5 times more then the strength of unretrofitted 9 inch x 9 inch columns. While 13.5 inch x 13.5 inch Retrofitted columns gave strength 1.35 times more than the strength of unretrofitted columns. Which shows that the strength was recovered by the damaged columns infect the columns became more strong due to retrofitting. Columns showed ductile behavior during failure.
10 Suggesting an empirical formula for Indian code of precast concrete on the maximum and minimum diaphragm forces in high seismicity, Bhruti Sharma
Diaphragm action is responsible for distributing lateral loads arising due to seismicity and wind loads among the lateral force resisting (LFR) members consisting of columns, bracings and shear walls in a typical reinforced concrete structure. Hence, the role of diaphragms is to provide structural integrity, i.e., maintain the floor systems gravity load carrying capacity while undergoing diaphragm action. Precast diaphragms could be designed as rigid or flexible depending upon the site and seismicity requirements. Too much of rigidity or flexibility is dangerous to structural behavior due to incompatible deflections and too large deflections respectively. Damage to precast concrete diaphragms is observed in many past earthquakes across the globe. About thirty large panel precast concrete roof panels sustained damage and collapse due to the failure of generating sufficient diaphragm action in the 2001 Bhuj earthquake in India. So, there is an immediate need to analyze and design the diaphragm for high seismicity. In our Indian Standard code of practice for precast concrete, there are no provisions for load distribution in diaphragm systems in high seismic zones. Here in this paper a formula for the distribution of loads in the diaphragms and an empirical formula for the maximum and minimum diaphragm forces have been suggested for the Indian code of practice for precast concrete structures.
11 Stress concentrations in single walled carbon nanotube reinforced metal and polymer composites under uniaxial loading, S A S P Sathurusinghe, W M N A P B Herath, H A R Subhashini, K R B Herath
Considering orthotropic elastic properties for the CNT and perfect bonding condition for the interface, a Finite Element (FE) analysis is herein carried out on a SWCNT reinforced composite system to obtain the stress distribution resulting from axial loading for the cases of matrix being metal and polymer. The high stress concentration locations are found to occur at the interface of the CNT and the matrix at the end-cap region. CNTs are found to provide exceptional reinforcement for composites under tensile loading. The results from this study also help to understand the load transfer mechanism between the SWCNT and the matrix.
12 Engineering assessment of coarse aggregates used in Peshawar, Muhammad Ayub, Qaisar Ali, Khan Shahzada, Amjad Naseer, Muhammad Shoaib, Umair Ayub
This paper presents the qualification of coarse aggregates obtained from various existing quarries in and around Peshawar city for their use in structure concrete. Out of the ten (10) four (4) quarries were experimentally investigated. The sites were selected on the basis of being easily accessible and productive. Various tests including Bulk Density, Soundness of Aggregates, Los Angeles Abrasion, Alkali-Silica Reactivity (ASR), Alkali-Carbonate Rock Reaction (ACR) and Petrographic Examination of Aggregates were carried out according to ASTM standards. The results of this study show that the aggregates investigated have no unstable form of Silica and Reactive Carbonates. The Alkali-Silica and Alkali-Carbonate Reactions have shown no expansion, therefore, the representative samples are considered harmless to be used in concrete. Based on the experimental study of this research, coarse aggregates from the mentioned sources (Bara River, Basai, Loye-Khawar and Zangali/Jani-Khawar) can be safely used in structure concrete works. Out of the above four sources Basai is found to be the best source for coarse aggregates.
13 Sensitivity of Pushover Analysis to Design Parameters-An Analytical Investigation, Ajay Goudar, Shilpa Koti, K. S. Babunarayan
The static pushover analysis is becoming a popular tool for seismic performance evaluation of existing and new structures. The existing building can become seismically deficient since seismic design code requirements are constantly upgraded and advancement in engineering knowledge. Further, Indian buildings built over past two decades are seismically deficient because of lack of awareness regarding seismic behavior of structures. The widespread damage especially to RC buildings during earthquakes around the world generated a great demand for developing a simple yet efficiently accurate new method known as pushover analysis for seismic evaluation. The expectation is that the non-linear static analysis popularly known as pushover analysis will provide adequate information on seismic demands imposed by the design ground motion on the structural system and its components and consumes very less time compared to non-linear dynamic analysis. In a real structure the strength of concrete and steel may not be the same as assumed in the analysis, it may be more or less, Since the output of the analysis is very much sensitive to design parameters, in the present thesis, attempt is made to understand the sensitivity of design parameters like strength of concrete, strength of steel and cover to reinforcement on performance of structures namely bare frame structure and frame with rigid slab and compare the variation in performance within these two.
14 Study on Performance Evaluation of Adhesive Anchors in Concrete, Anwar Shah, Qaisar Ali, Bashir Alam, Khan Shahzada, Rawid Khan, Naveed Ahmad
The purpose of this study is to evaluate the ability of single adhesive anchors to resist sustained tensile load when installed in concrete and to develop a rationale guideline for their design and selection. Currently, most of the designers follow adhesives manufacturers recommendations. Every manufacturer is claiming the best properties for its products through its product manuals, however, despite its widespread use, very seldom any one of these products have been tested in a laboratory to verify their actual properties. To evaluate the tensile strength of the epoxies used for reinforcing anchors, pull out tests were performed on the steel bars anchored at two different development lengths of 3 & 6 inches using the material of two manufacturers. This helped in recommending the minimum depth for the installation of anchors using epoxies. For the purpose of comparison pull out test were also performed on steel bars anchored, at two different development lengths 6 & 9 inches, using ready mixed grout. The results shown by the epoxies for 3 inches anchorage depth did not agree with the claims made by the manufacturers, however, the epoxies showed good results for 6 inches anchorage depth. For 9 inches or more anchorage depths the ready mixed grout showed good results than epoxies.
15 Performance of Pre-Wetted Sawdust as a source of Internal Curing of Concrete, Bashir Alam, Zahid Ullah, Faheem Ullah Jan, Khan Shahzada, Salman Afzal
In this research study the performance of pre-wetted sawdust as a source of internal curing for concrete was investigated. Primarily sawdust was used to reduce self-weight of concrete, however it was recognized that dry porous sawdust could absorb sufficient amount of water that could be an effective mean of internal curing. Pre-wetted sawdust was used to partially replace the sand and specimens were covered in polythene bags. Different trials were performed on sawdust lightweight concrete with internal and external curing and tested for compressive strength. Compressive strength results were compared with normal density concrete to draw conclusions.
16 Analysis of Composite Beams using Method of Initial Functions, Patel Rakesh, Dubey S. K, Pathak K.K.
Method of initial functions is used for the analysis of composite laminated beams. The distribution of bending and shear stresses in composite laminated beams are different from beams of small thickness. The equations of two dimensional elasticity have been used for deriving governing equations. The order of the derived equations depends on the stage at which the series representing the stresses and displacements are truncated. No assumptions regarding physical behavior of beams are made. The beam theories which are based on assumptions are of a practical utility in the case of beams of moderate thickness. However in the case of thick or composite beams it becomes difficult to obtain useful results using theories based on assumptions.
17 Evaluating the Effect of Bentonite on Strength and Durability of High Performance Concrete, Junaid Akbar, Bashir Alam, Muhammad Ashraf, Salman Afzal, Asfandyar Ahmad, Khan Shahzada
Two very basic possessions of concrete are being addressed by this research work i.e. Durability and Compressive Strength of concrete. The major variable that is introduced in the research work is Bentonite as partial replacements by weight of cement. The experimental program explained by this explosion contains two parts. The first part was to investigate the potential use of Bentonite to evaluate its impact on Compressive strength of High Performance Concrete (HPC). An HPC batch, properly mix designed was primed, aiming at strength of 6000psi. Super plasticizer was also introduced to attain high workability. Some part of the batch was treated for a Compressive Strength test. The second part of research work addresses its effect on Durability of concrete. For this purpose the rest of the batch was exposed to a cycle of wetting and drying in sulfate ironic atmosphere, the solution containing 50 g/l of Na2SO4. The durability was measured in terms of resistance offered to the penetration of sulfate ions into the concrete. Ultrasonic Pulse Velocity testing was performed for this purpose and the quality of concrete was checked. It was seen from the results that Bentonite resulted in poor early stage and good later stage Compressive strength when compared with Control samples. On the other hand it showed very good resistance to sulfate attack. Control samples which were exposed to sulfate environment were affected very harshly. The main conclusions drawn from this research work is that Bentonite can be used in a place where later stage strength is required. And for durability purposes it gives good results at every stage.
18 An Investigation on Confined Fiber Reinforced High Strength Concrete Beams in Flexure, Ch. Rambabu, T. Chandra Sekhar Rao, N. V. Ramana Rao
In this paper a study on behavior of ten under-reinforced concrete beams with fibers (Steel and Glass-fibers), and also with or without G.I wire mesh wrappings under flexural loading is presented. In general, addition of fibers improves the bending strength and ductility of the composite. The G.I mesh wrappings will provide the additional confinement to the fibrous concrete matrix. The test results show that flexural strength and ductility of confined fiber reinforced concrete beams is improved compared to un-confined fibrous beams. It is also observed that the enhancement in flexural capacity and ductility is more in beams with steel fibers than Glass-fibers.
19 Mitigating Sulphate Attack in High Performance Concrete, Bashir Alam, Salman Afzal, Junaid Akbar, Muhammad Ashraf, Khan Shahzada, Muhammad Ejaz Shabab
The research addresses the mitigation of Sulphate attack on concrete as it is considered one of the major degradation-causing phenomenons in the durability of concrete. The primary variable in the research was the introduction of Silica Fume as a 12% replacement by weight of cement. Super-plasticizer was also used in order to attain high strength and make the concrete more workable in the presence of silica fume. A concrete batch, with a proper mix design was prepared, aiming at a high strength of 6000psi. Part of the batch was tested for 28 days Strength and part of it was subjected to cyclic wetting and drying exposure to Sulphate-rich environment, the solution being 50 g/l of Na2SO4. The quality of concrete was measured by Non-Destructive Testing which showed an appreciable improvement in the resistance of concrete to Sulphate attack due to addition of Silica fume whereas the Normal concrete cylinders were affected severely in the Sulphate environment. The same concrete cylinders were tested afterwards for compressive strength under the Universal Testing Machine and the results showed an alarming reduction in strength of the normal concrete cylinders whereas the Silica fume made concrete cylinders showed small reduction in strength. The main conclusions derived from this study are that the use of Silica fume leads to a better performance of concrete in Sulphate rich environments although the strength may not be altered as desirable.
20 In-situ stress measurements for confirming the influence of topography on orientation of desilting chamber - a case study, D. S. Subrahmanyam
A stress measurement program was undertaken at Punatsangchhu H.E. Project stage-I during January 2010 inside desilting chamber for the determination of in-situ stress tensor by hydro fracture method. This test was required to freeze the orientation of desilting chamber vis. a vis. orientation of maximum compression (?H) which was found to be N 150?. The hydrofrac test was carried out at RD 100 and RD 150 inside an exploratory drift at dam-axis and approaching towards desilting chamber with a rock cover of 100 m. As it was only 100 to 150 m away from the portal a topography effect on the orientation of (?H) was not completely ruled out. So when the adit to desilting chamber reached at RD 360 with a rock cover of 410 m, it was necessary to carry out stress measurement to confirm the orientation of maximum compression (?H). The stress orientation as evaluated at RD 360m confirms the orientations revealed from earlier stress measurements at RD 100 and RD 150m.Thus it is recommended to freeze the direction of Desilting Chamber along N 150o. It also confirms that the earlier stress measurement results do not suffer from topography related influence.
21 Optimal Geometry of Pin-Jointed Plane frames using a Hybrid Complex Method, Bashir Alam, M. I. Haque, Qaisar Ali, Khan Shahzada, Syed Mohammad Ali, Afzal Khan, Muhammad Ibrahim
This paper describes a computational procedure of obtaining minimum weight design of pin-jointed plane frames using design variables that specify both the skeletal geometry and member sizes of the structure. The entire design space is decomposed into two subspacesthe geometric design space, and the member design space. The variables of the geometric design space contain the coordinates of the variable joints of the structure, while the variables of the member design space contain the cross sectional dimensions of the members. The optimal design vector of the geometric design space is found strictly by the mathematical programming technique, and the complementary part of the design vector in the member design space is found by the fully-stressed optimality criterion. To validate the applicability and proficiency of the proposed procedure a numerical problem has been optimized and the results are compared with the previous results available in the literature. The study demonstrates that the developed algorithm is capable of finding near-optimal design in a some what robust and efficient manner.
22 Earthquake resistance of structures using dampers - A Review, K. Krishne Gowda, K. K. Kiran
During the last decade more and more attention has been put to vibration mitigation of structures subjected to environmental (i.e. seismic and wind loads) and manmade (i.e. traffic or heavy machinery) loads. In this paper an overall control system is explained in brief and also various applications of control system. Now a day a Sevier Earthquake occurs over globally, it is necessary that structure build across the seismic zone built under considerations of seismic resistance. The seismic resistance can be done by using control devices. The control devices are damper. The damper can be classified into various categories based on its functions or control system. The control system classifications are Active, Passive, Hybrid and Semi active control system. Passive control system is internally energy develops, Active requires external power, Semi active requires partially power consumptions. Numerical applications of control system are explained. The overall conclusions say that Semi active control system is more suitable compare to other control system.
23 Increasing the sustainability of concrete by using Super Plasticizers - A Study , Syed Allah Bakash, B. Krishna Reddy
Sustainable development is the challenge of meeting human needs for natural resources, industrial products, energy, food, transportation, shelter and effective waste management while conserving and protecting environmental quality and the natural resource base essential for future development. It is well known fact that in the manufacturing 1 metric ton of cement produces 0.9 metric ton of CO2. To overcome this problem the use of cement in concrete and cement mortars should be decreased. This can be done by replacing the cement into other available cementetious materials or by using different admixtures. However most of the modern concretes almost always possess additives, either in the mineral form or chemical form. Particularly, chemical admixtures such as water reducers and set controllers are invariably used to enhance the properties of fresh and hardened concrete. In this review paper the superplasticizer which is an admixture to concrete is being used. Their addition to concrete or mortar allows the reduction of the water to cement ratio, not affecting the workability of the mixture, and enables the production of self-consolidating concrete and high performance concrete. This effect drastically improves the performance of the hardening fresh paste. Indeed the strength of concrete increase whenever the amount of water used for the mix decreases. However, their working mechanisms lack of a full understanding, revealing in certain cases cement-superplasticizer incompatibilities. These polymers are used as dispersants to avoid particle aggregation, and to improve the rheology of suspensions such as in concrete applications. Superplasticized concrete pumps easily and arrives workable. For maximum effectiveness, however, superplasticizers must be added to the mix at the right time.
24 Influence of Treated Water on the Early Age Autogenous Shrinkage of Cement Paste, Md. Rokon Hasan, Muhammad Harunur Rashid, S M Arifur Rahman, Salma Alam
Autogenous shrinkage of cement pastes both for early and later ages cause cracks in many cases because of improper setting. Since early age autogenous shrinkage normally considered as the time of 24 hours just after mixing water and without any moisture migration, it is really difficult to measure the early age properties. Because in this stage cement paste stands as semi liquid and starts to hardening. However in this stage there occurs considerable volume change due to autogenous shrinkage. The aim of this work is to investigate this shrinkage of cement paste at constant temperature and humidity for ordinary Portland cement and Portland composite cement using treated water with a non destructive technique. Also the performances for both cement was investigated using acidic, alkaline & mineral water. The non destructive experimental setup has been performed in six special type glass bottle, where three for ordinary Portland cement and rest for Portland composite cement maintaining the pH of water 5,7,10 respectively. And it has been investigated that besides composition of cement, pH of water also largely influences the shrinkage value in early stage. Also from the fineness of cement paste these shrinkage value is compared. It is observed that lowering the pH of water the performances of cement paste decreased for both cement. And the Portland composite cement shows greater shrinkage than ordinary Portland cement. Also with increasing fineness of cement shrinkage also increased. Therefore, this paper provides insight regarding how to interpret early age autogenous shrinkage, how treated water play a role, and comparative analysis of shrinkage in the early age.
25 Experimental Studies on Strength and Durability of Mortars Containing Pozzolonic Materials, C. M. Ravikumar, Sreenivasa M.B., K. Abdul Raheem, M. H. Prashanth, M. Vijay Sekhar Reddy
The paper discusses the effects of using different pozzolonic materials as a partial cement replacement material in mortar mixes. An experimental study of mortar made with Ordinary Portland cement (OPC) and 12% of OPC, replaced by different pozzolanic materials such as Fly Ash, Rice Husk ash, Silica Fume, Calcined Clay (Grog) and Slag (GGBS) were tested for the strength and durability properties, to determine the effect of these materials on mortar properties and was compared to control mortar mix. Mortar specimens were tested for compressive strength at age of 3, 7 and 28 days and flexural strength at age of 28 days. To investigate the mortar for its durability, the specimens after initial curing of 28 days were immersed in fresh water with solutions of 10% sodium sulfate (Na2SO4) and 10% magnesium sulfate (MgSO4) for another period of 3 months. Through this period, the specimens were tested for compressive strength at 60, 90 and 120 days to evaluate its durability.
26 Investigation of Styrofoam as Lightweight Aggregate, Bashir Alam, Zahid Ullah, Faheem Ullah Jan, Khan Shahzada, Salman Afzal
This research work utilized the laboratory evaluation of the performance of Styrofoam in concrete as lightweight aggregate by focusing on its ability to reduce dead load without significant reduction in compressive strength. Styrofoam particles of 0.50 inch-square sizes were used to partially replace (by volume) coarse aggregates. The study mainly focuses on the comparison of compressive strength and unit weight of concrete. Standard sized cylindrical specimens (612) were prepared for this purpose. The compressive strength and unit weight of normal density concrete, prepared at mix design ratio of 1:2:4 (cement: sand: coarse aggregate) were used as yardstick for comparison with Styrofoam lightweight concrete.
27 Influence of stone dust as partially replacing material of cement and sand on some mechanical properties of mortar, Tasnia Hoque, Muhammad Harunur Rashid, Md. Rokon Hasan, Ebna Forhad Mondol
Mortar is one of the most important components in reinforced concrete structural member. In reinforced concrete structures mortar have some inseparable influence. Lacking in mortar strength endanger the whole structure. Now a day it is seen that many structures fails due to lack of strength. So, the mechanical properties of mortar have some critical effect. In this paper an investigative experiment is reported on the mechanical properties of mortar modified by stone dust as replacing material of both fine aggregate and cement. An endeavour has been made to evaluate the appropriateness of stone dust as construction materials. Properties of mortar are investigated with the replacement of 25% and 50% of fine aggregate and also 5% of cement by stone dust. Cubes and briquette samples were casted and tested after a curing period of 3, 7 and 28 days. Several samples were made by using above proportion to get the effect on mortar. Results of this work have indicated that 25% replacement level exhibit higher strength than the controlled sample. Therefore, this paper provides insight regarding how to interpret mechanical properties of mortar, how stone dust as a partially material play a role, and comparative analysis between fresh mortar and modified mortar.
28 Adoption of Structural Soil and Water Conservation Technologies by Small holder farmers in Adama Wereda, East Shewa, Ethiopia, Tesfaye Gebre, Zerihun Mohammed, Menfese Taddesse, S. Chenchu Narayana
This study identifies factors that influence farmers decision to adopt the structural conservation measures introduced to selected sites in the Dabe and Goro Kebeles, in Adama wereda, East Shewa. The study also examines farmers acceptance and adoption of structural conservation technologies that were implemented by the various projects. A total of 92 sample farmers were selected and data about farmers acceptance and adoption of conservation technologies were collected using a household survey, interviews, focus group discussions and field observations. The data was analyzed using frequency, descriptive and the chi-square statistics. The result indicates that the majority of respondents totally removed the previously installed conservation technologies. However, the majority of the farmers accepted that the newly introduced conservation technologies were effective combating soil erosion and improving land productivity. The factors discouraging the farmers from adopting the technologies were found to be labour shortage, difficult designs to implement, lack of adequate extension service, shortage of land, distance of cultivation fields, and source of income. The study emphasizes that many of these problems were related to a lack of farmers involvement in the conservation efforts and suggests that future SWC interventions should follow a real farmer participatory approach in the areas. In addition, farmers should have a greater awareness of the economic significance of soil erosion on their cultivated fields; they need training on the impacts of erosion and the conservation technologies available to control soil loss; and farmers with labour shortages need to be provided with support that enables them to retain their conservation technologies.
29 Measuring specific heat of normal strength concrete and the comparison of the specific heat with different types of concrete, S. M. Abdullah Al Faruq, Md. Alamin, Md. Rokon Hasan, Md. Tozammel Haque, Salma Alam
Specific heat is the amount of heat that a unit mass of a material must gain or lose to change its temperature by a given amount. The specific heat of a material is associated with the heat capacity, except the specific heat doesnt depend on an objects mass, though it depends on the types of material. Specific heat measures the index of the facility with which concrete can undergo temperature changes. Specific heat is also related to thermal conductivity and thermal diffusivity. For this reason measurement of specific heat of concrete is very essential. The aim of this study is to build up an arrangement for measuring specific heat of normal strength concrete and the comparison of the specific heat with different types of concrete and also to observe the variation of current and voltage with respect to time. Unit weight, Voids, Moisture content and Specific Gravity was measured for measuring specific heat by using bricks khoa and stone chips as coarse aggregate and the samples are covered with and without glass wool. The specific heat of concrete varies with the mixing ratios of ingredients of concrete. The specific heat of concrete with denser mixing ratio is greater than concrete having looser mixing ratios.
30 Stabilization of Clayey Soil using Cement Kiln Waste, Y. Keerthi, P. Divya Kanthi, N. Tejaswi, K. Shyam Chamberlin, B. Satyanarayana
Day by day increasing demand of cement results in intense collection of kiln dust from cement plants. The disposal of this fine dust becomes an environmental threat. In order to overcome this problem, research is being carried out in different parts of the world to find out the economical and efficient means of using cement kiln dust (CKD) various applications like soil stabilization, cement production, pavements, waste product stabilization, and agriculture and cement products, etc. Keeping in mind the need for bulk use of these solid wastes in India, it was thought expedient to test these materials and to develop specifications to enhance the use of these industrial wastes in soil stabilization. In the course of the study, this research has been able to establish the reactions between soil and cement. It has been established that the chemical compounds found in soil; quartz, feldspar, dolomite, calcite, montmorillonite, kaolinite etc. react with the chemical constituents found in different identified chemical stabilizers. The purpose of using CKD, and the other additives, is to improve the texture, increase the strength and reduce the swell characteristics of the various soils. This paper represents the stabilization of clayey soil using cement kiln waste. The soil taken from Ravendrapadu in Andhra Pradesh containing different properties in various percentages is mixed with CKD in different proportions and parameters like dry density and moisture content are found out. By examining the values obtained ideal values are obtained at 50% proportional mix of CKD in total percentage.
31 Effect of diaphragm on the foundations of building structures with steel seismic base isolators , Abbas Haghollahi, Omid Ghiami Ardabili, Amir Tarighat
Seismic isolation is a technique of reducing the response of structure against earthquake. Using this kind of building systems , leads to dissipation of the principal frequencies of the reduces the seismic energy during the earthquake .The direct effect of using this system is the reduction of earthquake load and the destruction of buildings. The main concern of this paper is to find out the effects of using horizontal diaphragm on the seismic isolators which are erected on the foundations. By nonlinear modeling and analysis of steel moment resisting frame and lateral bracing systems in structures with different stories, beneficial results regarding to behavior of the seismic isolation system are obtained. Results of this study show remarkable effects of the foundation diaphragms on the behaviors of the structures.
32 Hydrological and Hydraulic Study of Bridges and Culverts, Nouman Khattak, Salman Afzal, Syed Azmat Ali Shah, Muhammad Ejaz Shabab, Navid Ahmad
This study discusses the hydrological and hydraulics study for bridges/culverts in order to estimate the 100-year water surface elevation at a given project site. Bridges (and sometimes very large culverts) are very expensive hydraulic structures which usually have a design period of 100 years. Most bridges fail due to overtopping of flood water. In Pakistan, due attention is usually not given to this important study, that result in the failure of bridges before reaching their design periods. In the current scenario, no one can deny the importance of this study especially after the destruction of bridges due to recent floods (July 2010) in Pakistan. This study is focussed on various hydrological and hydraulics procedures to calculate the 100-year flood discharge at a culvert site on Long Branch located under Guinea Road in Virginia, USA. For this purpose, we used Anderson method to estimate the discharges for various return periods. The bridge engineer can then fix the road level for the culvert keeping in view a suitable free board value. Such a structure will not be overtopped by a flood that has a recurrence interval of 100 years.
33 Effect of Saline Water on the Flexural Performance of Ferrocement Wall Panel, Milon K. Howlader, M. H. Rashid, Zahangir Alam
Ferrocement as a form of reinforced concrete constructed of hydraulic cement mortar strengthened with closely spaced layers of continuous and relatively small diameter wire mesh. It has been used worldwide as a construction material to provide better construction and rehabilitation of structures. Moreover, there may be structural deterioration of ferrocement due to the exposure of saline water. In this article, the flexural performance of ferrocement panels under normal and exposed in saline water was investigated. For this rationale, a series of thin mortar plate specimens of 275 mm 275 mm (width length) in size were casted with varying number of mesh layers, thickness and immersed condition. For the expedition of the effect of saline water, accelerated constant current corrosion test was performed. Mid-point loading test was done to measure the flexure performance of the specimens. Test results revealed that the flexural performance of ferrocement wall panel reduces due to the effect of saline water.
34 Combined effect of Bentonite and Silica Fume properties of High Performance Concrete, Junaid Akbar, Bashir Alam, Muhammad Ashraf
Two very basic possessions of concrete are being addressed by this research work i.e. Durability and Compressive Strength of concrete. The major variable that is introduced in the research work is Bentonite plus Silica Fume (CBS) together, as partial replacements by weight of cement. The experimental program explained by this explosion contains two parts. The first part was to investigate the potential use of Bentonite plus Silica Fume (CBS) to evaluate its effect on Compressive strength of High Performance Concrete (HPC). An HPC batch, properly mix designed was prepared, aiming at strength of 6000psi. Super plasticizer was also introduced to attain high workability. Some part of the batch was treated for a Compressive Strength test. The second part of research work addresses its effect on Durability of concrete. For this purpose the rest of the batch was exposed to a cycle of wetting and drying in sulfate rich atmosphere, the solution containing 50 g/l of Na2SO4. The durability was measured in terms of resistance offered to the penetration of sulfate ions into the concrete. Ultrasonic Pulse Velocity testing was performed for this purpose and the quality of concrete was checked. It was seen from the results that BS samples resulted in fairly good early and later stage Compressive strength when compared with Control samples. On the other hand it showed very good resistance to sulfate attack. Control samples which were exposed to sulfate environment were affected very harshly.
35 Behaviour of Infill Walls under Lateral Loads in Reinforced Concrete Frames - A Review, Syed Azmat Ali Shah, Khan Shahzada, Salman Afzal, Muhammad Ejaz Shabab, Nouman Khattak
In modern day construction practices, one of the most feasible choices of erecting concrete buildings is to construct concrete frame structures as it allows the contractors to follow a smooth pattern of work during the various construction stages with ease and appreciable economy. The frame members are infilled with concrete masonry units, bricks, cast-in-place concrete or wood etc. The design of reinforced concrete frames usually ignores the beneficial or adverse effects of incorporation of infill walls within a frame. The interaction of masonry units as framing elements and the adjoining frame members might not be noteworthy during static load analysis procedure however when the same reinforced concrete frame undergoes lateral drifts due to dynamic forces, the behavior of the infill walls becomes noteworthy. A review of the various approaches has been presented in this paper that addresses the performance of masonry infill walls under lateral loads i.e. the application of dynamic forces.
36 Construction management practices for demolition and renovation of structure in south-west region of Bangladesh: A Case Study, M. Jobaer Hasan, M. Yeasin Mostafiz, M. J. Hossain
Demolition is the tearing down of buildings and other structures for the beneficial purposes. Here the word management refers to coordinated works of demolition and renovation works with respect to time frame. The main objective of construction management is the cost effectiveness in conjunction with safety measures during construction. A good number of buildings, structures in south-western region of Bangladesh were damaged due to environmental effects, such as - salinity, corrosion of reinforcement and soil characteristics. The important thing is that, in south-west region workers are locally available at low rate than south-east region. In this study, mainly the demolition and renovation works of roof slab and some other parts of a students dormitory (Fazlul Haque Hall) in Khulna University of Engineering & Technology (KUET) which was damaged due to salinity and corrosion of reinforcement were analyzed by critical path method (CPM). It has found that if the contractor had applied CPM at the beginning of the project the firm could have saved at least 19 days for the work items of North block which was demolished manually. Demolition management deals with the demolition of those affected structures with reference to proper management for instant safety management, time management and cost management. In case of manual demolition, it requires more time than mechanical or explosive demolition. Moreover, it is difficult to maintain time frame because concrete strength is not same in each and every section so it is difficult to predict required time to demolish the structure.
37 Farmers perceptions and participation on Mechanical soil and water conservation techniques in Kembata Tembaro Zone: the Case of Kachabirra Woreda, Ethiopia, Tesfaye Gebre, Debebe Weldemariam
Soil erosion is one of the major causes of land degradation that resulted in low agricultural productivity in Ethiopia. In the study area, Soil erosion by water constitutes a threat to the maintenance of the subsistence living of the Ethiopia rural population. Efforts made in the earlier period efforts of soil conservation did not bring about significant results, mainly because of lack of bottom-up approach. Uprooting this past oversight and instating a participatory approach has since been strongly recommended as the right strategy which was being practices for some years now in the study area. This research analyses the extent of farmers perception and participation in the current SWC activities in the Doreba and Hobichika watershed, Kachabirra Woreda, Kembata Tembaro Zone. Formal household survey, informal and focus group discussions and field observation were used to generate the data. The result shows that the majority of the respondent farmers participated in the SWC against their will. The most important factor discouraging them from participating freely was the perceived ineffectiveness of the soil and water conservation structures measures under construction. Awareness about severity soil erosion as a problem, Participation in SWC activities, level of literacy, land be absolute private property and off-farm were found to be less significant in providing an explanation for the disinterest shown by most of the respondent farmers towards the SWC activities except farmers willingness of participation and adoptions of soil conservation. Therefore, the most important factors that require immediate consideration for SWC activities in the study area are: firstly, SWC structures have to be carefully designed and constructed taking into account ground realities in the study sites, and secondly, participation of the household farmers has to be through their own conviction regarding the effectiveness and efficiency of the soil conservation structures. In addition, Alternative soil and water conservation structures will have to be considered in this regard.
38 Significance of Silt Content and Void Ratio on the Hydraulic Conductivity of Sand-Silt Mixtures , S. M. Rezwan Hossain, Md. Abdul Qaiyum Talukder, Shariful Islam, Md. Rafiue Islam
In case of undrained and partially drained loading of granular soils with fines, hydraulic conductivities play a vital role on the pore pressure generation. 200 No. sieve has been used to separate silt-clay from sand. Silt and clay mixed has been dissolved in water. Consolidation tests have been performed on two types of sand with the mixture of 5%, 15% and 25% silt in it. Slurry of sand-silt mixture has been used to prepare sample as undisturbed condition for consolidation tests. From this research we can know about the properties of two types of sands (kushtia sand and khulna local sand) mixing with various amount of silts. The data evaluated from tests shows that with the decreasing amount of silt in the sand-silt mixtures hydraulic conductivities increase. On the other hand, for finer sand hydraulic conductivity is lower than comparatively coarser sand. If the permeability of sand is not good then it effect on the total effective pressure of the soil under the foundation of any structure as the rainwater cannot drained out. For good drainage system sand of a construction site should have high rate of hydraulic conductivity.
39 Effective Utilization of High Volume Flyash with Light Weight Aggregate in Concrete for Construction Industry, S. Lokesh, M. G. Ranjith Kumar, S. Loganathan
The selection of this title is to use fly ash, effectively and environment friendly nature in concrete construction. Fly ash is a waste material from thermal power plant is converted into light weight aggregate (i.e., production of fly ash based aggregates either by bonding or sintering technique) for use in concrete as porous light weight in nature. They are weaker than conventional normal weight aggregates and produce light weight concretes. Mortar portion is very important in achieving strengths in light weight aggregate concretes. Fly ash is also used as pozzolanic material for partial replacement of Portland cement in the light weight aggregate concretes. Such light weight aggregate concrete with high volume fly ash cement has all the attributes of high performance concrete i.e. excellent mechanical properties, lower permeability, superior durability and environmental friendly nature. Incorporation of silica fume in small quantities in high volume light weight aggregate concrete is likely to compensate the deficiency occurring in initial days. The results of the investigation reported here in, have shown that the light weight aggregate concrete made with cement mortar in combined use of fly ash with silica fume, has improved the strength development in initial days.
40 Effect of mineral admixtures on the properties of mass concrete - A review, Muhammad Ejaz Shabab, Khan Shahzada, Muhammad Ashraf, Muhammad Fahad
This study addresses the various aspects of massive concrete construction and one of the major problems associated with such type of concreting i.e. thermal cracking. A detailed review has been presented on the mitigation strategies of various researchers in controlling the problem of thermal cracking and temperature gradients caused during massive concrete structures. The mineral substitution techniques used in current day research have been qualitatively assessed and a better judgement has been proposed while utilizing the capabilities of such mineral substitutions. The experimental techniques adopted to investigate the thermal gradients established within massive concrete members have also been reviewed and a synopsis is presented. The behaviour of mineral admixtures with respect to their dosages in mass concrete specimen has been critically looked upon and the variation in the performances in establishing respective temperature thresholds are analysed. Moreover, the beneficial role of various mineral substitutions in controlling the cracking propensity of the concrete structures have been put forward by presenting a real-time case scenario for adaptation in future research studies in addressing the cracking behaviour of mass concrete specimen. Adiabatic temperature rise, rate of adiabatic temperature rise and the cracking temperatures in mass concrete specimen have been selected as primary point of research interest and the dosage rates of mineral admixtures kept as the variable while addressing the behavioural characteristics of crack generation and existence of steep temperature gradients.