Ⅲ级粉煤灰与镁渣耦合对C30混凝土抗压强度的影响研究

Coupling Effect of Ⅲ Fly Ash and Magnesium Slag on the Compressive Strength of Concrete

为有效和充分利用Ⅲ级粉煤灰与镁渣,以常用强度等级C30混凝土为研究对象,Ⅲ级粉煤灰取代率和镁渣掺量为因素,设计混合均匀试验方案U12(6,4),试验研究二因素耦合条件下混凝土的强度变化规律。对试验结果应用最小二乘拟合,建立了混凝土强度与粉煤灰取代率、镁渣掺量的非线性关系模型。因素效应分析表明:影响混凝土强度的主要因素是粉煤灰取代率,其次是镁渣掺量;Ⅲ级粉煤灰取代率的强度效应为负效应,镁渣掺量不大于49%时其强度效应为正效应,粉煤灰与镁渣的耦合效应为正效应;从强度和经济角度评价,以高粉煤灰取代率,较高镁渣掺量为混凝土配合比调控的最佳组合;对于C30混凝土,Ⅲ级粉煤灰与镁渣的合理组合为f=36%,m=5%。

In order to make use of gradeⅢ fly ash and magnesium slag effectively and fully,C30 concrete is commonly used as the research object,the gradeⅢ fly ash replacement rate and magnesium slag content is used as the factors.The mixed test scheme U12（6,4）is designed to do research on the strength rule of concrete by experiments in two factors coupling conditions.The nonlinear regression mathematical model is established by least squares fitting between the strength of concrete and fly ash replacement rate,magnesium slag content.Analyses show that：the main factors influencing the strength of concrete is fly ash replacement rate,followed by magnesium slag content.From the strength and the economic evaluation,high fly ash replacement rate and higher magnesium slag contents are the best combination of regulation of concrete mixture ratio;for concrete C30,reasonable combination of grade III fly ash and magnesium slag is f=36%,m=5%.