STUDY OF REPLACEMENT OF SAND BY EXPANDED POLYSTYRENE (PS) IN STRUCTURAL LIGHTWEIGHT CONCRETE

The search for more efficient concrete structures requires use of new materials in the developed of new concretes. With this objective, it was proposed in this study the substitution of Part of the medium sand of the lightweight structural concrete for expanded polystyrene (PS). It was replaced 5%, 10% and 20% of the sand to observe the changes in compressive strength, flowability, absorption, density and modulus of elasticity of these concretes. The results of the study show that there was an increase in the absorption and loss in the compressive strength and modulus of elasticity. Also, there was a significant increase in the flowability and reduction in the density of these concretes. Even with the replacement of part of the medium sand by expanded polystyrene, the concretes developed were classified as lightweight structural concretes, showing the applicability of this substitution in concrete designs.为研发性能更优异的混凝土结构，需在新型混凝土的开发过程中引入新型材料。基于此研究目标，本研究提出以聚苯乙烯泡沫（expanded polystyrene, PS）替代轻质结构混凝土中的部分中砂，分别设置5%、10%、20%三种替换率，以观测此类混凝土的抗压强度、流动度、吸水率、密度及弹性模量的变化。研究结果显示，此类混凝土的吸水率有所提升，而抗压强度与弹性模量则出现下降；同时其流动度显著提升，密度有所降低。即便通过聚苯乙烯泡沫替代部分中砂，所制备的混凝土仍可归类为轻质结构混凝土，证实了该替换方案在混凝土配合比设计中的应用可行性。