Research On Compressive Strength And Microstructure Of Waste Glass Powder Ultra High Performance Concrete

Due to the non-biodegradability of glass,serious environmental pollution is caused.Glass powder(GP)has high silicon content and amorphous properties,and is an excellent pozzolanic material for the concrete industry.The use of waste glass in concrete can greatly promote the recycling of waste glass.Preparation of Ultra-high performance concrete(UHPC)High cement consumption affects production costs and leads to waste of cement resources.In addition,the scarcity and high cost of silica fume.The production of quartz powder and quartz sand consumes natural resources,the production cost is high,and it also causes certain environmental pollution.Using waste glass to replace raw materials in UHPC has broad application prospects.At present,most researches on using waste glass to replace materials in UHPC focus on the substitution of cement.However,there are few studies on the substitution of quartz powder,quartz sand and silica fume in UHPC,which needs systematic research.In this paper,a series of experiments were carried out on the ultra-high performance of concrete with glass powder(GUHPC)after replacing UHPC raw materials with GP,and the different particle size GP,different content of GP,different raw materials were investigated The effect of the substitution on the compressive strength of UHPC,the evolution of microstructure and the change in packing density.(1)This paper studies the effect of GP on the compressive strength of GUHPC after replacing raw materials(cement,quartz powder,quartz sand and silica fume)in UHPC.It is obtained that when GP replaces quartz powder,the optimal GP particle size is 29.2 ?m,and the optimal blending amount is 100%.The 28-day strength of GUHPC can reach 97 Mpa.When GP replaces quartz sand I,the optimal GP particle size is 29.2 ?m,and the optimal blending amount is 100%.Its 28-day strength of GUHPC can reach 119.4 MPa.When GP replaces quartz sand II,the optimal GP particle size is 29.2 ?m,and the optimal blending amount is 10%.Its 28-day strength of GUHPC can reach 106.8Mpa.When GP replaces silica fume,the optimal particle size of GP is 42.6 ?m,the optimal blending amount is 30%,and its GUHPC's 8-day strength can reach 125.4Mpa.When GP replaces cement,the optimal GP particle size is 42.6 ?m,the optimal blending amount is 10%,and its GUHPC has an 8-day strength of 97.8Mpa.GUHPC test specimens are all under water standard curing.(2)The microstructure of GUHPC was analyzed by scanning electron microscope and X-ray diffraction test.The influencing factors of the addition of GP on the compressive strength of UHPC include: 1)GP with fine particle size has good filling effect;2)GP has good pozzolanic activity;3)GP contains Na2 O,which can provide a certain alkaline environment and promote the hydration reaction of cement.4)The specific surface area of GP is much smaller than that of quartz powder and silica fume.The water and high-efficiency water reducing agent required to lubricate and disperse particles is less than that of quartz powder and silica fume.Formation of calcium oxide.Therefore,an appropriate amount of GP can not only reduce the use of cement,quartz powder,quartz sand and silica fume,but also improve the compressive strength of UHPC.(3)The DeLarrard compressible stacking model is used,and the mathematical tool Matlab is used to establish a GUHPC mixture design model.Studies have shown that the finer the filler particle size,the higher the GUHPC packing density,the flatter and denser the corresponding microstructure,the better the GUHPC failure morphology,and the higher the corresponding GUHPC compressive strength.When quartz sand ? is replaced,its GUHPC strength decreases with the increase of the compaction density.This is due to the large amount of replacement of quartz sand,which reduces the framework effect of quartz sand on GUHPC.