Study On The Strength Curve Of Masonry Mortar Testing By Penetration Resistance Method

With the promulgation and implementation of JGJ/T 136-2017(hereinafter referred to as"Technical Regulations"),the standard of the Ministry of Construction,"Technical Regulations for Testing the Compressive Strength of Masonry Mortar",the penetration method is simple in operation,light in instrument,original The advantages of position test and intuitive results have been widely used in the detection of mortar compressive strength of existing buildings.The penetration method is a detection method for estimating the strength of the mortar according to the penetration curve given by the technical specification according to the penetration depth of the nail,but the detection value of the mortar strength is generated due to the difference between the masonry material and the masonry mortar.The impact,coupled with the recent promotion of non-sintered bulk materials,often results in the detection of the strength of such block masonry mortar on-site without the relevant standards as a basis for detection.Due to the above reasons and the status quo,the test of the strength of the masonry mortar for the non-sintered masonry of the cement mixed mortar and the premixed mortar was tested by the penetration method,and the test process and experimental results were introduced in this paper.In this test,the compressive strength of the standard mortar block,which is cured under the same conditions,represents the compressive strength of the wall mortar at the same age.Different blocks were used for the masonry of the wall.Among them,small concrete hollow blocks were selected as the main materials,and sintered porous brick walls were used as comparative tests.The experimental results of different blocks are compared with the strength curves given in the technical regulations,and the blocks with large measurement errors are re-regressed,or the original measurement curves are corrected.In this paper,after the abnormal data in the experiment is removed,the test results are statistieally analyzed.The penetration method is used to detect the actual strength of the mortar and the standard strength curve of the two walls of the mixing mortar and the ready-mixed mortar.Compared with the estimated value,the average relative error and the relative standard deviation both exceed the allowable range of the specification.Therefore,the strength curves of the sintered masonry and the small concrete hollow block are re-regressed for the two masonry mortars.