Strength Characteristics of Cement Treated and Expanded Polystyrene Mixed Lightweight of Waste Soil from the Construction Site of a Yangtze River Bridge in China

Abstract

In the past decades, the speed and scale of Chinese infrastructure construction have been enormous, and the resulting construction waste is also quite amazing, which has become a huge threat to environmental protection. If the pollution-free engineering utilization of the construction waste can be achieved at a low cost, it will undoubtedly be a great benefit for the country and the people. Therefore, a preliminary experimental study was conducted to investigate the strength characteristics of the cement treated and expanded polystyrene mixed lightweight. The waste soil (muddy clay and fine sand) as the main component of the lightweight mixture is taken from a foundation construction site of a Yangtze River Bridge which connects two eastern coastal cities, Zhenjiang and Yangzhou. With different mixture ratios and additives of the cement treated and expanded polystyrene mixed lightweight, a series of cubic samples were tested by the unconfined compressive strength test, and collections of standard cylinder samples prepared by hand were inspected by the conventional triaxial shear test. Then, a good exponential relationship between the uniaxial compressive strength and the cement mixing ration was founded, and a logarithmic relationship was captured between the compressive strength and curing time within a period of 28 days after the specimens were made. Samples made of different soil as raw materials have different strengths, but all of these specimens show a strain-hardening and stable behavior. Results show that the mechanical strength characteristics of the cement treated and expanded polystyrene mixed waste soil mainly depend on the proportions of lightweight mixture.