About the author:

Shanghai Key Laboratory of Engineering Structure Safety, Shanghai Research Institute of Building SciencesCo., Ltd., Shanghai 200032, China

Abstract:

The current standard JGJ/ T 136—2017 Technical specification for testing compressive strength ofmasonry mortar by penetration resistance method is only applicable to determine the compressive strength ofmixed mortar and cement mortar, and is not applicable to determine the compressive strength of lime mortarcommonly used in modern masonry-timber structure. Brick walls and cubic lime mortar test blocks weremade according to the volume mix ratios of 1 ∶ 1,1 ∶ 2 and 1 ∶ 3 for lime and yellow sand, respectively.The mortar penetration test of the brick walls and the corresponding compressive test of the cubic mortar testblocks were conducted at 28d, 60d, 120d and 150d. The correlation between the penetration depth and thecompressive strength of the cubic mortar test blocks was statistically analyzed, and the strength test curvefor compressive strength of lime mortar by penetration resistance method was established. There is aconsiderable discrepancy between the derived curve and the curve in current standard. The tendency is thatthe smaller of the penetration depth, the lower of the calculated compressive strength,whereas the larger ofthe penetration depth, the higher of the calculated compressive strength. Compared to the current standardcurve, this curve is more suitable for lime mortar.