改善搅拌过程提高混凝土强度

Improving concrete strength based on the mixing process

为了提高混凝土的强度,围绕混凝土的拌和过程,分别从活化水、2次搅拌工艺以及振动搅拌设备3个方面开展了提高混凝土强度的试验研究。对拌和混凝土的关键组分水,通过高压电场处理,使其具有较强的物理、化学活性,促使拌和过程中的水化反应更加充分,并加快水化反应和凝结硬化速度。研究结果表明:与普通水的对比试验表明活化水提高了混凝土硬化强度;采用多步骤的2次搅拌工艺,促使拌和过程水泥浆体内水灰比梯度形成,降低过渡区的水灰比,改善过渡区孔隙结构,提高砂石等骨料界面的粘结强度,与传统搅拌工艺的对比试验表明,2次搅拌工艺综合提升了混凝土的整体性能;通过在搅拌机内设置深度激振器,采用振动作用与强制搅拌相结合的工作装置,消除拌和过程中的水泥颗粒团聚,降低混合物粘度和内摩擦力,使水泥颗粒快速均匀分散,水化反应更加彻底,与普通强制搅拌机对比试验表明,振动搅拌能明显改善混凝土的微观均匀性,提高了硬化强度。

Based on analyzing the concrete mixing procedure,this paper conducted experimental research to improve concrete strength by respectively using the activated water,secondary mixing process and vibratory mixer.As the critical components of concrete,the water was activated by using a certain electrical device to enhance the physical and chemical activity of water,which can make the hydration reaction of mixing process more sufficiently,and speed up the hydration reaction and condensation rate of hardening.The results show that the activated water can improve the concrete strength in comparison with ordinary water.The secondary mixing process can be used to promote the formation of a gradient of water-cement ratio in cement paste,reduce the water-cement ratio of the transition zone in the mixing process,improve the pore structure of the transition zone,and enhance the bonding strength of the aggregate interface.The contrast test with the traditional mixing process shows that secondary mixing process synthetically enhances the overall performance of the concrete.Adepth vibration exciter installed in a compulsory mixer can combine the vibratory activation with forced mixing in one working device which can be used to break the clusters of cement particles,reduce the viscosity and inner friction of the mixture,speed up the uniform distribution of the cement particles and make the hydration reaction more thoroughly during mixing process.The contrast experiments with conventional forced mixer show that vibratory mixing can significantly improve the microscopic uniformity of concrete and hardening strength.