An Experimental Study On The Preparation Of High-performance Grouting Material From Limestone Manufactured Sand

As the demand for grouting material increases and the output of river sand decreases,machine-made sand,a substitute for river sand,is widely used in the research and production of grouting material.Among them,limestone is often used as the main raw material for the production of machine-made sand because of its wide distribution and stable properties.Compared with another commonly used machine-made sand,quartz-made sand,limestone-made sand has low cost,rougher surface and good interface bonding.The strength is higher than the quartz stone machine-made sand of the same grade.However,the original content of limestone machined sand is too large,which leads to greater adsorption of the water reducing agent,which affects the fluidity and strength of the product.The difference in particle size results in a large specific surface area,which will increase the cement consumption of the grouting material,so it is usually only used as part of it.Aggregate is used in grouting material.With the emergence and continuous progress of dry sand making methods,the gradation and fineness modulus of limestone machine-made sand have become controllable,and the particle size problem has been gradually solved.The use of limestone machine-made sand is of great significance for reducing the cost of grouting material and protecting the environment.This article refers to and combines the modified fineness modulus and gradation optimization method to design and optimize the particle gradation of limestone machine-made sand,and use all-limestone machine-made sand as the grouting aggregate,which will affect the performance of the high-performance grouting material of all-limestone machine-made sand.Water-to-binder ratio,mortar-to-sand ratio and other factors have been specifically tested and researched,and a high-performance grouting material for full limestone machine-made sand with good fluidity,high strength,good stability,and micro-expansion is formulated to meet the needs of maintenance and reinforcement.And other engineering requirements.The main test process and conclusions are as follows:(1)The presence or absence of large particle size(2.36?4.75mm)of machine-made sand under the same fineness modulus will make the compressive and flow properties of the grouting material differ greatly.For this reason,the large-diameter size of limestone machine-made sand has been studied.(2.36?4.75mm)The influence of the dosage on the performance of the grouting material,research shows that the performance is better when the dosage is about 10%.According to the modified fineness modulus and gradation optimization method,the particle gradation of limestone machine-made sand is designed and optimized.It is believed that the performance of the grouting material is better when the modified fineness modulus is2.57,2.67,and 2.77.(2)Through the controlled variable method and the orthogonal experiment method,the mortar-sand ratio of the high-performance grouting material for all-limestone machine-made sand is researched and designed to be 1.0.The influence of three mineral admixtures of fly ash,silica fume and mineral powder on the performance of machine-made sand grouting material was studied,and the optimal ratio of mineral admixture to the cementing material was determined to be 10% of fly ash and mineral powder.10%,silica fume 5%.The expansibility of magnesium oxide and sulphoaluminate-calcium oxide expansion agents and their influence on the fluidity and compressive strength of the high-performance grouting material for all-limestone machine-made sand were studied,and 5% sulphoaluminate-oxidation was finally determined.Calcium is used as the source of expansion for fully machined sand grout.(3)Through the controlled variable method,the effects of water-binder ratio,type and amount of water reducing agent,and amount of defoamer on the performance of high-performance grouting material for all-limestone machine-made sand were studied,and the optimal ratio of grouting material was finally determined.(4)The high-performance grouting material of all-limestone machine-made sand has higher cost performance,good engineering application effect,and broad prospects.When limestone machine-made sand is used for bearing grouting material,the optimal modified fineness modulus is 2.37.After all the aggregates of the bearing grouting material are replaced with limestone machine-made sand,it has excellent performance and high cost performance.