Study On The Rebound Method To Test Mortar Strength In The Non-sintered Brick Works

Rebound method is a way to predict concrete (mortar) strength by rebound value (ratio ofthe rebound distance and the initial length of the spring) as a quota. It works as aspring-driven hammer to hit the concrete (mortar) surface to measure the distance the hammerbounces back through fillip bar (dowel). Since the measurement is on the concrete (mortar)surface, rebound method belongs to a surface hardness method which is based on thecorrelation between hardness on concrete (mortar) surface and strength of concrete (mortar).Now the theory and technology for rebound method on concrete testing has becomemature in China but the method on mortar is still in the initial stage though it has been reflectedin the specification. The national standard GB/T50315-2011(standard for site testing ofEngineering) has given the relevant provisions of the rebound method on mortar whose premiseis applied to the presumption of mortar strength only on Clay Bricks or sintered porous brickmasonry but there is no provision of the mortar rebound method on non-sintered brick.Based on the above, we use its resources and associated conditions to do experiments, todo analysis and to get this paper when Sichuan Academy of Building Research is carrying outthe preparation of the technical standards of the non-sintered brick works site testing. this paperis a study on mortar rebound method for non-sintered bricks which is focused on the content ofthe non-sintered brick mortar rebound method, on getting non-sintered brick fitting curves ofmortar rebound method by experiments and on giving some preliminary answers for thequestions which is proposed by a number of experts and scholars.Theoretical analysis and comparison shows that it is similar for rebound method ondetermination the strength between non-sintered brick mortar and sintered brick mortar so thatwe can do some experiments to measure the mortar strength on non-sintered brick based onsome methods and conclusions on sintered brick. By experiments and analysis this paperobtained the non-sintered brick mortar strength curve, obtained that Specification strengthcurve considered carbonation depth is debatable. The carbonation depth is a factor, but thedegree of influence is not so much emphasis on specification. On practical engineeringapplication, we can ignore the depth of carbonation influence on strength of mortar anddirectly calculate the strength of mortar by the rebound value.For sintered brick and sintered brick are different in materials, this paper built thenon-sintered brick strength curve based on sintered brick strength curve.The establishment ofthe curve extended the scope of application of the rebound method, filled a blank in the fieldof application of the rebound method so that the mortar rebound method for field detectionmethod is more accurate and universal. At the same time, along with the progress of the paper there have been lots of certain deficiencies and shortcomings on experiment methods andanalysis basis. These deficiencies and shortcomings are given along the thinking and directionof this paper to continue to go down.