芝麻白的物理特性
　芝麻白石一种耐火性很好的材料.石材在温度超过500℃以后,强度降低较明显,含石英质的石材还发生爆裂.出现这种情况的原因是:石材在火火高温作用,沿厚度方向存在较大的温度梯度,由于内外膨胀大小不一致而产生内应力,使石材强度降低,甚至使石材破裂;石材中的石英晶体,在573℃和870℃还会发生晶形转变.体积加大,导致强度急剧下降,并出现爆裂现象;含碳酸盐的石材(大理右、石灰石),在高温下会发生分解反应,分解生成CaO,其强度五莲红和五莲花低,且遇水会消解成ca(OH)2.

Physical properties of sesame white　

Sesame Bai Shiyi kinds of fire resistance of good materials. Stone after temperature over 500 ℃, the strength decrease obviously, containing quartz stone also burst. Reason: this is the case of stone material in the fire, the fire temperature, temperature gradient along the thickness direction is larger, the internal stress due to internal and external expansion size inconsistent, make stone material strength is reduced, and even make the stone burst; Stone of the quartz crystal, at 573 ℃ and 870 ℃ will happen crystal shape shift. Volume increase, lead to strength fell s五莲红五莲花石材harply, and occurrence blowout phenomenon; Containing carbonate stone (marble, limestone from right), will happen in the heat decomposition reaction, the decomposition generated CaO, its strength is low, and the water will dissolve into the ca (OH) 2.&nbs五莲石材厂p;