高温后合成纤维混凝土的强度试验研究

Experimental research on strength of synthetic fiber reinforced concrete after high temperatures

研究了普通混凝土(NC)、聚丙烯纤维混凝土(PPFRC)和聚丙烯腈纤维混凝土(PANFRC)在常温及300,600,1000℃高温后的抗压强度和抗折强度,分析了高温加热方式及加载条件不同的影响。研究表明,300℃高温下混凝土的劣化主要受升温速率的影响;600℃以上高温下混凝土的劣化主要受温度的影响。掺入低掺量的PP纤维和PAN纤维可缓解混凝土的高温劣化,从而提高高温后混凝土的抗压强度和背火面加载时的抗折强度。

The compressive strength and the flexural strength of Normal Concrete（NC）, Polypropylene Fiber Reinforced Concrete （PPFRC） and Polyacrylonitrile Fiber Reinforced Concrete （PANFRC） under normal temperature and after different high temperatures of 300℃ , 600℃ , 1 000℃ are investigated, and the influences of different high-temperature heating methods and loading conditions are analyzed. The results show that, the deterioration of concrete under high temperature of 300℃ is mainly influenced by heating rate, while the deterioration of concrete under high temperature upwards of 600℃ is mainly influenced by temperature. Mixing PP fiber or PAN fiber with low content can mitigate the high-temperature deterioration of concrete, with the result of improving the compressive strength of concrete after high temperature and also improving the flexural strength of concrete when loading on the unexposed surface after fire.