基于耐候性试验的外墙外保温体系性能研究

STUDY OF BEHAVIOR OF EXTERNAL WALL INSULATION SYSTEM BASED ON WEATHERING TEST

基于大尺寸耐候性试验,结合数值模拟,研究两种典型外墙外保温体系耐候性试验结果与数值模拟计算结果的相关性。结果表明:耐候性试验中测得的温度场与数值模拟计算得到的温度场吻合良好,数值模拟得到的抗裂砂浆层温度应力与试验中的开裂现象具有一定的相关性。对于聚氨酯保温体系,数值模拟中抗裂砂浆层温度应力越大,耐候性试验中墙体表面裂缝条数越多;温度应力越小,裂缝条数越少。合理地使用胶粉聚苯颗粒保温浆料,可以减少保温墙体防护层裂缝数量,从而提高外保温墙体的耐候性。当参考温度取为15℃时,热-冷循环中,墙体表面承受拉压循环,热-雨循环中,墙体表面主要承受压力。

It was studied the relationship between test and computation results of two typical external wall insulation systems based on large-sized weathering test and numerical simulation. The results showed that the thermal field measured in large-sized weathering test agreed well with that of the numerical simulation; the calculated temperature stress in anti-crack mortar had a good correlation with the cracking phenomenon in large-sized weathering test. For the Polyurethane insulation system,the greater the calculated temperature stress in anti-crack mortar was,the more surface cracks on the wall were; the smaller the calculated stress in anti-crack mortar was,the less surface cracks on the wall were. Rational use of the colloid powder polystyrene particles thermal insulation mortar could reduce the number of cracks on the wall and increase the durability of external wall insulation system. As the reference temperature was 15 ℃,the wall surface was exposed to tension and compression cycle in the hot-cold cycles; and the wall surface was exposed to compression in the hot-rain cycles.