复合硅烷材料对混凝土干缩干裂的抑制效果

采用溶胶合成法,将正硅酸乙酯(TEOS)与异丁基三乙氧基硅烷乳液合成出一种复合硅烷材料,通过混凝土平板裂缝试验,研究了复合硅烷材料对不同强度等级混凝土抗干缩裂缝的作用效果。结果表明:混凝土表面涂覆复合硅烷材料后,干缩裂缝明显减少,C40混凝土表面光洁平整,未发现裂缝,C50混凝土表面仅出现为数不多的微裂缝(<0.1 mm)。随着水泥胶材用量的增加,混凝土表面的开裂情况越发严重,未进行涂覆处理的C50混凝土最大宽度裂缝超过1 mm。扫描电镜分析表明,由于TEOS的渗透结晶作用,在混凝土表层C-S-H凝胶明显增多,表面更加致密,同时由于硅烷良好的抑制水分散失的能力,复合硅烷材料在新拌混凝土表面形成抗裂层,抑制了表面的干缩干裂。

Protective effect of silane material on drying shrinkage crack of concrete

A new kind of permeable waterproof material had been synthetised by ethyl silicate(TEOS) and isobutyl silane as raw materials through sol synthesis in this paper.The protective effect of compound silane on drying shrinkage crack of different strength level concretes were tested by the crack test of concrete slab.Test results showed: for the slab with coating silane,the surface of the C40 concrete was smooth after the blow wind,and undetected cracks.For the C50 the surface was only appeared to be very few small cracks (<0.1 mm).With the increase of cement content,the cracking of concrete surface was more serious.And the maximum width fracture of C50 concrete without coating slab was more than 1mm.Scanning electron microscope result showed,it could be found that the apparently increased of C-S-H gel in the concrete joining TEOS,the osmotic crystallization had been highlighted.In combination with the surface hydrohate film,the water ability of compound silane could be prevented,and the protective layer could be formed on the surface of the newly mixed concrete to prevent the surface cracking caused by weathering.