改性脂肪族减水剂对混凝土抗裂性能的影响

Crack resistance of concrete mixed with modified sulfonated aliphtic series superplasticizer

通过引入对氨基苯磺酸和木质素磺酸钠,合成具有磺酸基(—SO3H)、氨基(—NH2)和羟基(—OH)的改性脂肪族减水剂(MSAF),并在此基础上研究了MSAF对混凝土塑性收缩与抗裂性能的影响,通过XRD分析,探讨了MSAF对水泥铝酸盐水化产物的作用。结果表明:与普通脂肪族减水剂相比,MSAF具有更好的保水作用和空间位阻效应,使混凝土早期塑性收缩降低,开裂面积减小。MSAF能够抑制C3A的水化进程,降低早期的水化反应温度,减少混凝土早期裂缝的产生。

By introducing sulfanilic acid and sodium lignosulphanate,the modified sulfonated acetone formaldehyde （MSAF） high efficient water reducer was synthesized with sulfonic group （-SO3H）, amino group （-NH2） and hydroxyl. The plastic shrinkage and crack resistance of concrete mixed with MSAF was investigated, and effect of MSAF on assemblage of aluminate hydrates in cement paste was investigated by XRD. Experimental results indicated that the plastic shrinkage and the cracking area of concrete mixed with modified sulfonated aliphtic series superplasticizer decreased,compared with aliphtic superplasticizer. MSAF has better water dispersion effect and space steric effect which is benefit for crack resistance of concrete. MSAF can inhibit the hydration progress of C3A,reduce early hydration reaction temperature, and reduce the early crack of concrete.