Preparation And Properties Of High-performance Composite Insulation Mortar And Crack-resistance Mortar

Expanded polystyrene (EPS) insulation system is mainly consisted of EPS composite insulation mortar layer, crack-resistance mortar layer and interface mortar layer. However, EPS particles display big density difference and poor compatibility when mixed with inorganic binder, which contributed to the current EPS composite insulation mortar show poor workability, low bond strength with concrete base, and be prone to induce defects as hollowing, shedding and so on. Moreover, the low compressive strength of current EPS composite insulation mortar limits its popularization and application in the roof insulation engineering. Meanwhile, the crack resistance of present crack-resistance mortar is still a poor, a certain amount micro-cracks are produced under stress. Therefore, it is of great importance to improve the compatibility between EPS particle and cement, the bonding strength and compressive strength of EPS composite insulation mortar.In this paper, a self-made EPS surface-treated agent was used to improve the compatibility between EPS particle and cement, and the EPS composite insulation mortar with high bond strength was prepared. The mechanical strength of the mortar was enhanced by employing silica fume, sepiolite fiber and silt ceramisite, so that it could be used in roof insulation engineering. The effect of hybrid fiber, treated crumb rubber, capillary crystalline additive to the crack resistance of crack-resistance mortar were investigated, thus the high crcak resistance mortar was made. The following conclusion can be drawn in the paper.1. Harden silicate coat could be formed on the surface of EPS particle after surface treatment process, so the high density difference and poor compatibility between EPS particle and cement could be solved successfully. The composite insulation mortar employing treated EPS particle shows good workability, improved compressive strength and excellent bond performance with concrete base.2. The proper amount of silica fume added to the mortar by the way of replacing equivalent weight cement could enhance the compressive strength and bonding strength to some extent. When appropriate content of sepiolite fiber was employed, the thermal conductivity was decreased while the compressive strength and the toughness of insulation mortar were increased obviously. The addition of silit ceramisite could significantly enhance the compressive strength of insulation mortar.3. The toughness and crack resiatance of the mortar were improved obviously by adding hybrid fiber which consisted of trefoil polypropylene fiber and basalt fiber. The compatibility between crumb rubber and cement became better after the crumb rubber was treated with Na2Si03 solution and NaOH solution respectively, the toughness and impact resistance of crack-resistance mortar were enhanced greatly. In contrast, the crumb rubber treated with Na2SiO3 exhibited better improvement effect to crack-resistance mortar than NaOH treatment crumb rubber. The addition of capillary crystalline additive could increase the crack resistance of mortar, and endue the mortar with crack self-healing performance.