Asian journal of civil engineering
Volume:9 Issue: 1, February 2008

This paper presents a qualitative evaluation of uni-axial shake table test results for a halfscale reinforced concrete house designed by the Indonesia Aid Foundation (IAF). Thebuilding is intended to provide a quality-controlled design by being precast at a factory anddelivered to the site for assembly, thus providing a living area for a family of approximatelysix people. In addition, the house is to be base isolated on used car tires filled with sand to approximate more technical rubber bearing base isolators available for use in construction and seismic retrofit today. The base isolation system was extremely effective and did not allow shear force to be transferred into the reinforced concrete walls, resulting in virtually no damage.

Monitoring of workability is a critical issue for high performance concrete (HPC) since HPCis susceptible to small changes in mixture proportions that have a direct impact on hardened properties. In the present study, rheological tests were performed with a modified set up of parallel plate rheometer. Correlation between rheological parameters and the mix design parameters has been obtained and correlation charts have been used for the design of HPC mixtures. The procedure presented in this paper takes into account estimation of rheological parameters at the design stage.

In the present study, the effect of concrete cracking on the lateral response of buildingstructures has been investigated and discussed. The research work related to the study of effect of concrete cracking on its stiffness has been surveyed. The controversies in theexpressions of the prime parameter related to the cracking of the reinforced concrete are also discussed. The modification factors and equations recommended in literature as well as in different country standards to introduce the non-linearity of concrete are also given. The framed building design examples are presented for quantitative effect of lateral response incorporating the concrete cracking under seismic loading based on Indian seismic code.

In this paper a simple ant algorithm based on ant system is proposed for nodal orderingproblem to reduce the profile of sparse matrices. In this algorithm, a local search procedure is also included to further improve the profiles. The results are compared to those of a graph theoretical profile optimization algorithm. Examples are included to illustrate the performance of the present approach.

This paper presents an investigation into the development of stresses in anchorage zone in prestressed post-tensioned concrete beam using the finite element analysis. A finite element computer code on the platform of a supercomputer PARAM 10000 is developed and employed for the present study. A parallel algorithm for matrix inversion method isdeveloped and implemented in the presented finite element code. Concentric and eccentric prestressing forces are applied for prestressing of the beams. Effect of Poisson’s ratio over the bursting tensile force developed in the anchorage zone is studied and an equation to compute the magnitude of bursting tensile force by incorporating the effect of Poisson’s ratio is proposed. Development of spalling zone is also investigated and it was found that due to eccentric loading, stresses of higher magnitude were developed in this zone. Supercomputer PARAM 10000 is used to carry out present analysis and time reduction has been achieved by using multiple processors of the supercomputer PARAM 10000. At the end the performance of the developed parallel code is studied and presented.

In the present study, the effect of curing procedure on the compressive strength development of cement mortar and concrete incorporating ground granulated blast furnace slag is studied. The compressive strength development of cement mortar incorporating 20, 40 and 60 percent replacement of GGBFS for different types of sand and strength development of concrete with 20, 40 and 60 percent replacement of GGBFS on two grades of concrete is investigated. The compressive strength of cement mortar and concrete obtained at the ages of 3, 7, 28, 56, 90, 150 and 180 days. Tests results show that the incorporating 20% and 40% GGBFS is highly significant to increase the compressive strength of mortar after 28 days and 150 days respectively. The magnitude of compressive strength of mortar for standard sand is higher than the magnitude of river sand. Incorporating 60% BFS replacement is showing lower strength at all ages and water-cement ratio for both types of sand. The compressive strength of OPC concrete shows higher strength as compare to the GGBFS based concrete for all percent replacement and at all ages. Incorporating 40% GGBFS is highly significant to increase the compressive strength of concrete after 56 days than the 20and 60% replacement. Among GGBFS based concrete 40% replacement is found to beoptimum.

The Boumerdes 2003 earthquake which has devastated a large part of the north of Algeria has raised questions about the adequacy of framed structures to resist strong motions, since many buildings suffered great damage or collapsed. To evaluate the performance of framed buildings under future expected earthquakes, a non linear static pushover analysis has been conducted. To achieve this objective, three framed buildings with 5, 8 and 12 stories respectively were analyzed. The results obtained from this study show that properly designed frames will perform well under seismic loads.

This work presents on the one hand the possibility of the use of the industrial waste ofmineral origin (calcined clay bricks) for the manufacture industry of a mortar based onmixed fine aggregates (natural and artificial) and on the other hand a contribution to theimprovement of the mechanical properties of the mortars containing mixed sands (dune sand and calcined clay).The purpose of this initiative is the analysis of the physical and chemical properties of sandsused (dune sand and calcined clay sand), as well as the characteristics of the mortar made with mixed sand such as, the workability, the density and the mechanical responses (compressive and flexural strengths: Rc and Rf). In this work, we substituted the natural sand (dune sand) by artificial sand (waste bricks) at various ponderal contents (0, 25, 50, 75 and 100%). The results obtained show that the substitution of the natural fine aggregates (dune sand) by 25% of calcined clay (artificial sand) by ratio to the ponderal weight gives an acceptable mechanical strength in relation to the mortar of reference (0% of clay sand substituted).