EFFECT OF DIFFERENT MODIFICATIONS ON PHYSICAL AND MECHANICAL PROPERTIES OF EPS-CEMENT BASED COMPOSITE MATERIALS

摘要

Expanded polystyrene (EPS) - cement composite materials are characterized by light weight and good thermal insulation, in order to improve the physical and mechanical properties of EPS-cement composite materials. This paper studied the effect of modified EPS particles with different concentrations (1-10) of triethanolamine (TEOA) and silane coupling agent (SCA) on compressive strength, elastic modulus, thermal conductivity, and water absorption of EPS-cement composite material. It was found that adhesion between EPS particles and cementitious material paste effectively improved by modification. The compressive strength and elastic modulus of the composite could significantly be improved after the EPS particles modified by appropriate TEOA and SCA concentration. In particular, the early strength of the composite could be improved after the EPS particles modified by TEOA. Compared with the control, the compressive strength was increased by 57.32 at the age of 3 days. The compressive strength of EPS-cement composite samples was increased by 22.2 and 21.14 at 7and 28 days. Its modulus of elasticity was increased by 8 . TEOA and SCA concentrations did not influence significantly water absorption and thermal conductivity of the EPS mixes. The thermal conductivity of the EPS specifications ranged from 0.21 to 0.32 w/(m·K), the cumulative water absorption after 24 hours of all mix specifications ranged from 11.27 to 13.24 . In general, the modification effect of TEOA was better than that of SCA, and the recommended concentration of TEOA was 5-8 .The study showed that EPS cement-based composites could have good thermal insulation properties and good mechanical properties after modification.