Adjustable multiple stress induced cracking device for concrete

Abstract

The invention provides an adjustable multiple stress induced cracking device for concrete. A test device is internally provided with a steel crack induction unit. The induced cracking device is characterized in that the test device adopts a bottomed steel frame with adjustable height; the steel crack induction unit with adjustable angles and height is adopted and is laid along the length direction of the bottomed steel frame with adjustable height; meanwhile, the effective height of the bottomed steel frame is larger than the height of the steel crack induction unit. By adjusting the height of the steel crack induction unit and the bottomed steel frame, the device farthest weakens the effects of the maximum grain size of coarse aggregates on the cracking test results and realizes the adjustability of induced crack initiation force. The device realizes test on the anti-cracking performance of the concrete with maximum coarse aggregate grain size not more than 40mm and has the characteristics of high testing accuracy, wide applicability, simple operation and the like. Under the premise of ensuring the testing accuracy, the device shortens the testing time and reduces the randomness of occurrence of concrete cracks.

Description

technical field [0001] The invention relates to a concrete induced cracking device capable of providing adjustable multi-channel stress, which can adjust the size and direction of induced stress and the height of the device according to the maximum particle size of coarse aggregate in concrete, and can effectively and quickly test the crack resistance of concrete . Background technique [0002] The crack resistance of concrete materials has become a hot issue in the engineering field, but there is no unified test device for evaluating the crack resistance of concrete. The more commonly used ring method and plate method also have certain defects. The test time of the ring method is long and the sensitivity is poor; while the cracks of the plate method are random and have no obvious regularity, so that the test results cannot accurately evaluate the cracking performance of concrete. The new flat plate method that has appeared recently, by placing parallel tiled steel crack ge...

AI Technical Summary

Problems solved by technology

[0002] The crack resistance of concrete materials has become a hot issue in the engineering field, but there is no unified test device for evaluating the crack resistance of concrete. The more commonly used ring method and plate method also have certain defects. The test time of the ring method is long and the sensitivity is poor; while the cracks of the plate method are random and have no obvious regularity, so that the test results cannot accurately evaluate the cracking performance of concrete

The new flat plate method that has appeared recently, by placing parallel tiled steel crack generators in the test device, although it can implement an equivalent induction effect on cracks, shorten the time for cracks to appear and reduce the randomness of cracks, but The steel crack generator does not take into account the maximum particle size of the coarse aggregate and the content of the coarse aggregate in the concrete, which makes the uniformity of the concrete material in the slab worse. Above the top of the steel crack generator, the concrete The coarse aggregate content of the crack generator is significantly lower than that on both sides of the crack generator, which directly affects the accuracy of the test results

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