Abstract: In order to determine the compressive strength of cement-based grouting material components in strengthening reinforced concrete structures, two types of small-diameter core samples with a height-to-diameter ratio of 1 and diameters of 50 mm and 70 mm are designed and fabricated according to the requirements outlined in the “Technical Specification for the Application of Cement-Based Grouting Materials” (GB/T50448-2015). An experimental study on the compressive strength of cement-based grouting materials detected by the small-diameter core drilling method is carried out. The results indicate that the compressive strength of both standard specimens and small-diameter core samples increase with age, exhibiting a rapid growth rate in the early stages and a gradual slowdown in the later stages. The compressive strength of the 70 mm small-diameter core samples is higher than that of the 50 mm samples, with lower dispersion in compressive strength. Based on the least squares method, power function equations are derived to estimate the compressive strength relationships between the 50 mm and 70 mm small-diameter core samples and the standard specimens. Considering the fitting results and error analysis, it is recommended to use the 70 mm small-diameter core samples for assessing the compressive strength of cement-based grouting materials.

Key words: cement-based grouting material, small-diameter core sample, compressive strength, least squares method, power function

摘要： 为确定钢筋混凝土结构加固中水泥基灌浆料实体构件的抗压强度,根据《水泥基灌浆材料应用技术规范》(GB/T 50448-2015)中的要求,设计制作了高径比为1,直径为50、70mm的两种小直径芯样试件,开展小直径芯样钻芯法检测水泥基灌浆料抗压强度试验研究。结果表明:水泥基灌浆料标准试块和小直径芯样试件的抗压强度随龄期的增长而提高,前期抗压强度增长速率较快,后期增长速率减缓;70mm小直径芯样试件较50mm小直径芯样试件的抗压强度高,且其抗压强度离散性较小;基于最小二乘法,得到了50、70mm小直径芯样试件与水泥基灌浆料标准试块抗压强度之间的幂函数推算公式。综合考虑拟合效果和误差分析,建议采用70mm小直径芯样检测水泥基灌浆料抗压强度。

关键词: 水泥基灌浆料, 小直径芯样, 抗压强度, 最小二乘法, 幂函数