结构混凝土标养期后的强度变化规律研究

Study on the Change of the Strength of Structural Concrete after the Standard Curing Period

为了解结构混凝土在标准养护期后其强度随着时间推进的变化规律,本研究采用的研究方法是在结构混凝土浇捣后的28～120 d的时间段,利用ZC3-A型回弹仪来测定现场结构混凝土的回弹模量,并采用表面碳化深度进行强度换算值的修订,以此来得出标准养护期后结构混凝土的真实强度.分析结果显示工程结构混凝土在自然环境的养护条件下,其后28 d的强度会继续随着养护龄期的增长而稳步提升,用多项式公式对28～120 d的强度变化规律进行拟合,在结构混凝土自然养护28 ～ 80 d期间,其真实强度能提高20％～ 30％,而养护龄期在80 d后强度基本保持不变.

In order to understand the variation laws of the strength changes of structure concrete after standard curing period with time going, the resilient modulus of the structure concrete after 28 d-120 d was measured ZC3-A resiliometer and strength conversion value was revised by surface carbonization depth to reflect the actual strength of the structure concrete after standard curing period. Analysis results showed that twenty-eighth days later the strength of the structural concrete in curing conditions of natural environment continued to upgrade steadily with the increase of curing period. A polynomial formula was fitted to express the strength variation from the 28th to 120th day. The strength can be improved by 20% - 30% with natural curing for 28d to 80d. After that the strength almost kept the same.