Experimental Study on Light Weight Concrete-Filled Steel Tubes

Tests on steel tubular columns of rectangular and circular sections filled with normal and lightweight concrete were performed to investigate the behavior of such columns under axial loadings. Comparison between normal and lightweight concrete filled steel columns for different column cross-sections using Euro Code 4 and BS 5400 codes was also conducted. The test results showed that both types of filled columns failed due to overall buckling; while hollow steel columns failed due to local buckling at the ends. According to these results, further interest was taken onto the replacement of normal concrete by lightweight concrete due to its low specific gravity and thermal conductivity

Comparative Study of Load Carrying Capacity of Steel Tube Columns Filled with Lightweight Concrete and Normal Concrete

Tests on steel columns filled with normal concrete and lightweight concrete were carried out to investigate the actual behavior and the load carrying capacity of such columns. Eight full scale rectangular cross-section columns filled with lightweight aggregate concrete and normal weight aggregate concrete, four specimens each, were tested under axial loads for comparison purposes. The results showed that using lightweight concrete filling instead of normal concrete filling will reduce the weight of columns. At the same time, a high load carrying capacity is achieved

Dissolution of Gypseous Rocks under Different Circumstances

The influence of temperature, flow velocity, gypsum content, salinity of solvent and hole diameter on the amount and rate of dissolution of gypseous rock samples was investigated. The rock samples were obtained from the proposed Al-Fat’ha dam site located approximately 280km to the north of Baghdad city. The gypsum content for these samples ranged from 16% to 90%. Dissolution tests were carried out with the aid of a special system that was modified and manufactured to allow passing water at different speeds through a drilled hole along the center of the rock samples. The amount of dissolution of gypsum was determined under different conditions. The results showed that the amount and rate of gypsum dissolution increased with increasing the temperature of the test. The effect was more pronounced on rock samples with low gypsum content. Increasing the flow velocity also increases the amount and rate of gypsum dissolution. With this parameter, the effect of gypsum content was marginal. Increasing the salinity of the solvent (using low percentages of NaCl additives) has a great influence on the amount and rate of gypsum dissolution, and further increase in the salinity exhibited a marginal increase in the amount of dissolution when compared with the lower salinity concentration. The Tigris river water (as a natural solvent) exhibited a negligible effect on the amount and rate of gypsum dissolution. Increasing the diameter of the hole along the center of the sample increases the inside area exposed to water and hence generates more dissolution

Experimental study of concrete made with granite and iron powders as partial replacement of sand

AbstractGranite Powder (GP) and Iron Powder (IP) are industrial byproducts generated from the granite polishing and milling industry in powder form respectively. These byproducts are left largely unused and are hazardous materials to human health because they are airborne and can be easily inhaled. An experimental investigation has been carried out to explore the possibility of using the granite powder and iron powder as a partial replacement of sand in concrete. Twenty cubes and ten beams of concrete with GP and twenty cubes and ten beams of concrete with IP were prepared and tested. The percentages of GP and IP added to replace sand were 5%, 10%, 15%, and 20% of the sand by weight. It was observed that substitution of 10% of sand by weight with granite powder in concrete was the most effective in increasing the compressive and flexural strength compared to other ratios. The test resulted showed that for 10% ratio of GP in concrete, the increase in the compressive strength was about 30% compared to normal concrete. Similar results were also observed for the flexure. It was also observed that substitution of up to 20% of sand by weight with iron powder in concrete resulted in an increase in compressive and flexural strength of the concrete

Assessment of Rainwater Harvesting Systems in Poor Rural Communities: A Case Study from Yatta Area, Palestine

Yatta is a town located nine kilometers south of Hebron city in the West Bank of Palestine. The town houses over 100,000 people of which 49% are females and has a population that doubles every 15 years. Yatta has been connected to a water network since 1974 serving nearly 85% of its households. The water network is old and inadequate to meet the needs of the population. Water supply made available to the area is limited, estimated at 20 L/capita/day. Residents are thus forced to rely on water vendors who supply water that is 400% more expensive with a lower quality compared to municipal water. Therefore, rainwater harvesting is a common practice in the area, with the majority of households owning at least one cistern. Rainwater harvesting is of great socio-economic importance in areas where water sources are scarce and/or polluted. In this research, the quality of harvested rainwater used for drinking and domestic purposes in Yatta was assessed throughout one year. A total of 100 samples were collected from cisterns with an average capacity of 69 m3, which are adjacent to cement-roof catchment areas of 145 m2 average surface area. Samples were analyzed for a number of parameters including temperature, pH, alkalinity, hardness, turbidity, total dissolved solids, NO3, NH4, chloride and salinity. Results showed that most of the rainwater samples were within World Health Organization (WHO) and Environment Protection Agency (EPA) guidelines for chemical parameters. Microbiological contents such as total Coliforms and faecal Coliforms bacteria were tested. The research also addressed the impact of rainwater harvesting systems on different socio-economic attributes of the local community through a questionnaire that had been filled out before any sample was collected