EVA改性EPS混凝土微观结构及性能研究

Properties and Microstructures of EPS Lightweight Concrete Modified with EVA

为了改善聚苯乙烯(EPS)轻集料混凝土中EPS颗粒与水泥砂浆界面的黏结性能,提高EPS轻集料混凝土的力学性能,采用乙烯-醋酸乙烯酯(EVA)乳液对EPS颗粒表面进行改性,并对改性前后EPS轻集料混凝土的力学性能作了对比试验,结合扫描电镜、X射线衍射和红外光谱,分析了EVA乳液对EPS轻集料混凝土性能的影响机理.结果表明:EVA改性改善了EPS轻集料混凝土的微观结构,使其内部孔洞数量减少,孔洞尺寸趋于减小;使水泥水化更为充分,水化产物组成得以优化,EPS轻集料混凝土的180 d抗压强度和抗折强度得到提高.

In order to improve the combination ability of the expanded polystyrene（EPS） beads and the cement mortar in the EPS lightweight concrete,and the mechanical properties of this concrete,the ethylene-vinyl acetate copolymer（EVA） emulsion was used to modify the EPS surface.Mechanical properties of EPS lightweight concrete were tested;the influence of EVA on EPS lightweight concrete had been analyzed by means of scanning electron microscope（SEM）,X-ray diffraction and infrared spectroscopy spectrum.Tests results indicate that EVA emulsion can improve the EPS concretes microstructure,the quantity and size of inner pore can be decreased,hydration of cement can be more sufficient and composition of cement hydration product can be improved obviously.Accordingly,the 180 d compressive strength and flexural strength of the EPS concretes are enhanced.