Research On The Material Of Paste-rich Cemented Sand And Gravel

Cemented gravel dam is a new type of dam that combines the advantages of concrete faced rockfill dam and roller compacted concrete gravity dam.The strength of the cemented sandy gravel dam is guided by the concept of "suitable materials and suitable construction",and strives to build the dam with less waste.As a new type of cemented gravel dam protective layer material,paste-rich cemented sand and gravel is very different from traditional concrete in terms of mix design and material composition.Aggregates do not need to be screened,prepared and washed.Less dosage and larger water-to-binder ratio are the distinctive features of rich cement-bonded sand gravel.Therefore,it is of great significance to comprehensively grasp its mechanics and durability,and to provide parameters for the design of the protective layer of cemented gravel dams.This paper has carried out experimental research on the mechanical properties and deformation properties of slurry-rich cemented gravel,and the impermeability,frost resistance,and anti-wear durability of paste-rich cemented sand and gravel.The antifreezing effect in cemented sand gravel and the effect of epoxy resin on improving the erosion resistance of paste-rich cemented sand and gravel.The following results and conclusions have been achieved:(1)The effects of parameters such as gas content,fly ash content,and sand rate on the compressive strength of paste-rich cemented sand and gravel were investigated.The recommended range of mixing ratio parameters of paste-rich cemented sand and gravel is proposed.At the same time,the deformation properties of the grout-rich cemented sand gravel are studied.The results show that the grout-rich cemented sand gravel has good deformation ability,and because of the small amount of glue,the content of the fly ash is high,so the temperature rise is low The risk of cleft palate is lower.(2)The effects of the amount of fly ash on the frost-resistant properties of the pasterich cemented sand and gravel and the application of a new type of microcapsule anti-freeze additive in the paste-rich cemented sand and gravel were studied.The results show that when the fly ash content is 40% to 50%,the slurry-rich cementitious sand gravel still has good frost resistance;when the microcapsule antifreeze admixture content is 0.15%,the paste-rich cemented sand and gravel is antifreeze.The effect is the best,which is comparable to the frost resistance of 4.9% gas-rich slurry-bound cemented gravel.At the same time,the impermeability of slurry-rich cemented gravel was studied.The results show that the impermeability of slurry-rich cemented gravel is significantly higher than that of bulk cemented gravel,and the impermeability level can reach W12;the impermeability of paste-rich cemented sand and gravel is improved by adding air-entraining agent.(3)The effects of parameters such as the amount of cementitious materials,the amount of fly ash,and the sand rate on the erosion resistance of paste-rich cemented sand and gravel were investigated,and an index system of erosion resistance was established.At the same time,the effect of epoxy resin on improving the anti-wear properties of paste-rich cemented sand and gravel is systematically studied.The results show that the anti-wear performance of epoxy-rich paste-rich cemented sand and gravel is affected by factors such as the type of epoxy resin and the concentration of the diluent;Epoxy resin can significantly improve the anti-abrasion performance of slurry-bound cemented gravel.