复合防水剂对脱硫石膏砌块力学性能和防水性能的影响

The influence of compound waterproof agent on mechanical and waterproofing performance of desulfurized gypsum blocks

利用固体废弃物脱硫石膏制备的砌块耐水性差、浸水后强度明显降低,并且会产生严重的泛霜现象,影响其外观和力学性能,限制了其推广应用。基于此,使用甲基硅酸钠、二甲基硅油和聚甲基氢硅氧烷分别双掺作为复合防水剂,研究其对脱硫石膏砌块的力学性能和防水性能的影响,结果表明:脱硫石膏砌块随着聚甲基氢硅氧烷和甲基硅酸钠复合防水剂掺量的增加,抗压强度和抗折强度先减小后增大,软化系数变大;当聚甲基氢硅氧烷和甲基硅酸钠的掺量分别为0.30%、0.25%时,砌块的接触角为108°,防水性能良好。

The blocks prepared with desulfurized gypsum as a solid waste has poor water resistance.After being soaked in water,their intensity will decrease greatly,even cause serious frost on them,which may negatively affect their appearance and mechanical properties and restrict their applications.Because of the above mentioned,sodium methylsilicate,dimethylsiloxane and polymethylhydrosiloxane were double-doped and employed as different compound waterproofing agents respectively to study the effect of them on both the mechanical properties and waterproof performance of desulfurized gypsum blocks.The results show that with the increase of the content of polymethylhydrosiloxane and sodium methylsilicate in the desulfurized gypsum blocks,their compressive and bending strength firstly drops and then goes up and the softening coefficient increases.As the content of polymethylhydrosiloxane and sodium methylsilicate is 0.3%and 0.25%respectively,the contact angle of the block is 108°and presents excellent waterproofing performance.