Study on in-situ shear test of roller-compacted concrete and its shear strength failure criterion
The in-situ shear test of roller-compacted concrete is a reliable method for evaluating the shear strength characteristics of this type of concrete in real-world engineering applications.This study conducted in-situ tests on roller-compacted concrete specimens under four different working conditions using specialized equipment for shear test.The aim was to compare the shear characteristics of the specimens under varying levels of compressive stress and interlaminar interval time.The test results were used to generate load-displacement curves,which were then fitted using the Weibull-GUO Zhenhai full curve model.The ultimate shear strength was determined using the octahedral strength failure criterion.The findings indicate that the shear strength of the concrete test blocks with layers increases as the normal positive stress increases.Conversely,the shear strength of compacted concrete decreases with the increase of interlayer interval time.Among all the test blocks,the highest shear strength of roller-compacted concrete was observed when the interlayer interval time was 8 hours and the normal stress was 3MPa.This shear strength value was 0.83MPa higher than that observed at an interlayer interval time of 72 hours.The load-displacement curve was well-fitted by the Weibull-GUO Zhenhai full curve model,demonstrating good agreement between the model and the measured curves.Additionally,a strength failure criterion considering the interval time between layers was proposed based on the octahedral strength theory.These results provide a necessary theoretical foundation for determining the in-situ shear constitutive model and failure criterion of roller-compacted concrete.