Development And Application Simulation Analysis Of A New Environmental Protection Shotcrete Accelerating Agent

Wet shotcrete technology is widely used in tunnel construction engineering.In order to improve the construction quality,reduce the rebound rate and dust concentration,and reduce the harm to the health of construction workers,this paper prepared a new environmental accelerator to improve the quality of tunnel construction.The molar ratio of aluminate accelerating agent has a great influence on the environmental accelerating agent.Therefore,in order to reduce the rebound rate and dust concentration of concrete,it is necessary to improve the molar ratio of the accelerating agent in order to prepare a better environmental accelerating agent.In addition,the mix ratio of wet shotcrete of the accelerating agent is also very important.According to the design concept of this mix ratio and the verification of field investigation and test,we determined the optimal mix ratio according to the different strength levels of shotcrete.In order to verify the rationality of the mix ratio and In this paper,the effectiveness of the new environmental accelerator is simulated numerically by using discrete element simulation method and UDEC simulation software.The results show that:(1)for accelerator mother solution,KOH,Na OH and Al(OH)3 were added into the configuration of new environment-friendly accelerator mother solution.When the molar ratio of potassium/sodium to aluminum was controlled at 1.2:1,the accelerator mother solution would be uniformly stabilized.In the new environmental accelerating agent in the addition of polyacrylamide,triethanolamine,water reducing agent,stabilizer,etc.,accelerating agent mother liquor compound,in order to develop a new accelerating agent.(2)the concrete with the new accelerating agent can effectively reduce the rebound rate and dust concentration of the concrete,and can effectively improve the performance of the concrete.(3)mixing ratio of wet shotcrete.Considering the mix ratio of wet shotcrete of different strength grades C20,C25 and C30,and studying the different ratios,the mix ratio of concrete strength to meet the standard requirements is obtained.In addition,through the experimental study,it is shown that the performance of the concrete on site is up to the standard,and when the amount of accelerating agent is small,the rebound rate of the concrete is low,when the average amount of accelerating agent is 2.24%,the rebound rate is 16.67%,the performance of the new concrete meets the requirements.(4)regarding the optimal spray layer thickness.According to the different surrounding rock grades and different joint support conditions,the numerical simulation was carried out with UDEC software,and the results obtained the optimal spray layer thickness of the tunnel initial support,and when the optimal thickness was achieved,the tunnel surrounding rock could have a good supporting effect.