基于遗传算法的板材成型过程早期凝固强度建模与仿真

在冬季,水泥预制板生产过程中存在凝固时间长,生产效率低的问题。为此根据HYDCEM模型结合实际生产过程建立了一种基于遗传算法求解水泥预制板材早期抗压强度的方法。首先根据HYDCEM模型建立水泥预制板材早期凝结强度随温度及时间变化的强度发展模型。然后利用有限差分法求解水泥预制板保温过程的动态传热情况,结合强度发展模型得到水泥预制板材各网格点强度变化数据。最后,通过遗传算法对强度评判模型进行求解,结果表明遗传算法在求解早期抗压强度过程中具有很好的适应性,建立的水泥预制板早期抗压强度模型对生产过程有很好的指导作用。

Effect of Silica Fume on Early Performance of Precast Concrete with Early Strength Agents

The effect of silica fume on the early performance of precast concrete with an early strength agent was investigated.The ternary compounding technique of silica fume,fly ash and early strength agent were used to examine the compressive strength,heat of hydration,hydration products,and microstructures of the precast concrete.The experimental results showed that the optimum amount of silica fume in the precast concrete was 9%.Silica fume filled the fine pores between the cement particles.However,the cement hydration was mainly influenced by the waterto-cement ratio and cement particle size.As the hydration reaction continued,silica fume provided more nucleation sites,and the characteristic volcanic ash reaction increased both the hydration degree and hydration rate of the early strength agent doped cementitious materials.