摘要：
This paper highlights significant findings from focusing on developing a sustainable lightweight aggregate (LWA) concrete, which replaced Portland cement partially with municipal solid waste incineration fly ash (MSWI FA) and all of the conventional coarse aggregate with LWA sintered by MSWI FA, shale, and sludge. A series of four experiments, differing in dosage of MSWI FA and aggregate, were conducted for this project. The results of this study generally showed that appropriate amount of MSWI FA substitution for cement has no significantly lowered the compressive strengths of LWA concrete, while it can lower the oven-dry density and the thermal conductivity. The optimum performance of LWA concrete (after 28 days of curing) is as follows: (1) slump flow of 700 mm, (2) compressive strength of 30.14 MPa, (3) dry apparent density of 1.66 g/cm3, (4) thermal conductivity of 0.73 W (m K)−1; the mixture ratio of LWA, fly ash, cement, and fine sand is 3.0: 0.1: 0.9: 2.0 based on dry weight. Meanwhile, the results of leaching test are much lower than the concentration limits of hazardous constituents of hazardous waste identification standard (GB/T 5083.3-2007) and landfill standard (GB16889-2008).
摘要：
The farmland soil and creek sediments in different depth in the mining area were sampled, and their content of 238U,226Ra and 232Th were determined by gamma spectrometric method to assess the impact of the soil environment by single index method. The result shows 232Th was not influenced on soil in survey area. 226Ra influenced more seriously than 238U on farmland soil, meanwhile, the farmland soil at downstream of tailings dam was contaminated seriously by radionuclides than at other places. For creak sediments ,adit water resulted in more serious pollution by 238U than 226Ra, however, tailings erosion resulted in more serious pollution by 226Ra than 238U.
