| Fly ash and slag processing to become a big problem of China’s industrial production,in recent years many researchers conducted will fly ash and other polymer as gelling material research,with fly ash and slag as main ingredients,in under the action of alkali excitation,can give full play to the activity of slag and fly ash,mixed with water after a series of physical chemistry,can develop from plasticity slurry hard rock body.And it can bond granular materials together to form a solid whole,with higher strength and better durability.Therefore,it is a key problem to study the preparation of concrete with ground polymer cement and solve the technical problems in engineering application.In this paper,the properties of ground polymer gelling materials under different alkaline excitation conditions were studied at 9:1,8.5:1.5,8:2,7:2.5 and 7:3 of slag and fly ash.The study shows that the best ratio of slag fly ash is 8:2.The XRD analysis of samples under different excitation conditions showed that quartz was less active in the alkaline excitation process,which resulted in A large amount of quartz in the polymer slurry.In the cementite,A series of c-s-h,c-(A)-s-h,n-(C)-a-s-h and n-a-s-h co-existed.The infrared experiment results of gelling materials show that the gels of geopolymers all contain chemically bound water,and the active silicon group in the water glass takes part in the polymerization reaction.In addition,two carbonation reactions that may occur in the preparation and testing process of geopolymers gelling materials generate CaC03 and Na2C03.The NMR analysis of the cementitious materials showed that the pore strength was greater than 0.1 m,and the strength decreased with the increase of the larger pore porosity.According to the preliminary experimental results,the mix proportion design of ground polymer concrete was carried out,and orthogonal experiments were conducted to study the strength,durability and deformation performance of ground polymer concrete by taking water-binder ratio,sodium silicate modulus and alkali content as factors.The experimental results show that when the water-binder ratio,alkali content and sodium silicate modulus are 0.4,6%and 1.0,respectively,the strength of ground polymer concrete reaches the maximum value of 75.3mpa,and the alkali content has the most significant influence on it.From mercury injection test,it can be seen that the most significant influence on the strength of ground polymer concrete is multiple damage holes,and the ratio of high water-binder to concrete is about 50%.With the increase of multiple damage holes,the strength of ground polymer concrete decreases,while the influence of other three kinds of holes is small.When the water-binder ratio is 0.45,the alkali content is 6%,and the sodium silicate modulus is 1.0,the frost resistance is the best,and the same alkali content has the most significant effect on it.According to the analysis of the pore structure,when the content of small and medium air bubbles(0～100 m)is high and the distribution is uniform,the concrete will show good frost resistance.When the water-binder ratio,alkali content and sodium silicate modulus were 0.4,5%and 1.0,the chloride penetration resistance of GPC was the best,and the water-binder ratio had the greatest influence.The strength ratio of GPC prism to cube decreased with the increase of water-binder ratio.With the increase of alkali yield,it first increased and then decreased.As the modulus of sodium silicate increases,it decreases gradually.The maximum elastic modulus of geopolymer concrete is 6.3 when the water-binder ratio is 0.45,the alkali content is 6%,and the modulus of sodium silicate is 1.Through range analysis,it can be seen that the influence of various factors on the elastic modulus of geopolymer concrete is>sodium chloride content>water-binder ratio.The elastic modulus of ground polymer concrete is higher than that of ordinary concrete,but the ratio of elastic modulus of ground polymer concrete with different proportions is different from that of ordinary concrete.The deformation of ground polymer concrete is basically the same as that of ordinary concrete. |
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