Abstract: Steel-concrete-steel (SCS) sandwich construction combines the advantages of both steel and concrete and finds application in numerous areas such as bridges, protection against impact and blast loads, flooring system etc. Shear connector is a critical component of SCS system. In the present study, two new configurations of bi-directionally inclined shear connector are proposed. Response behaviour of SCS beams with bi-directionally inclined connector is obtained through numerical investigations. Finite element models of SCS beams are generated by using a simplified approach that employs solid, plate and beam elements to represent concrete, cover plates and shear connector respectively. Behaviour of concrete is represented using concrete damaged plasticity model, while steel behaviour is modelled by using bilinear stress-strain curve. Beam is simply supported and is subjected to a central concentrated load. Nonlinear static analysis is carried out to obtain load-deflection response. Numerical model is validated by solving a SCS beam with through-through connectors, which was experimentally investigated in literature. Responses from bi-directionally inclined connectors are compared with that of through-through connectors. Bi-directionally inclined connector is found to be more ductile compared to that of through-through connector, while the load carrying capacity remains same. Parametric study is carried out by varying the cover plate thickness, angle of inclination and diameter of the connector to study their influence on the behaviour of the steel-concrete composite beam.

Abstract: This paper is an extension of the work published in year 2010 in which compressive strength of plain concrete confined with Ferrocement was estimated using mathematical models and compared with 55 experimental results. In this paper, predictive model of compressive strength for plain concrete confined with Ferrocement has been developed by using MATLAB Artificial Neural Network (ANN) simulation. Out of 55, 19 experimental results are selected for training of multilayer feed forward neural network. Comparative analysis of the results showed that compressive strength estimated by ANN predictive model are very close to the experimental results than existing theoretical models.

Abstract: Slum population has been increasing in Bangladesh over the last three decades along with the growth and expansion of cities and towns. But slum facilities are very much unsatisfactory for them due to the lack of proper water supply and sanitation system. Therefore, the major portion of the households use unsafe latrine and deposit their children’s excreta into road side drain and open places, which pollutes water sources, groundwater and the general environment. As a result, majority of the population in Bangladesh suffer from different kinds of water and excreta-borne diseases that aggravate their poverty situations. So, the main objective and essential goal of the study is to investigate the water supply system and sanitation facilities in urban slums of Bangladesh. During the study period, data has been collected by questionnaire survey from each slum households (15 slums and 5324 households in RCC). However, the hygienic practice has been found to be significantly low among the all households in slums although they have enough knowledge about it. The study has showed that majority slum households use tube well water for drinking but significant numbers of them are found to use open latrine for defecation. Normally, pit and water seal latrines are found which are partially hygienic. These may cause ground water contamination depending on the soil characteristics and distance between the water sources and latrines. The open disposal of excreta pollutes the nearby water bodies, canals and drains causing severe environmental pollution. Many motivational work and idea marketing from government and NGO sides help to improve their awareness level.