Preparation And Properties Of Bamboo Fiber Modified One-part Alkali Slag Pavement Materials

In order to solve the problem of high CO2 emission during cement production,this paper selects low-carbon and environmentally friendly alkali-inspired materials to replace cement as binder for the preparation of concrete pavement materials.Selecting slag/fly ash as precursor and sodium hydroxide/sodium carbonate as alkaline exciter,uses response surface method for experimental design,and investigates the performance of one-component alkali slag cementitious materials under different water-cement ratio,sodium oxide equivalent and sodium carbonate dosing conditions with the help of performance characterization of flow rate,7d compressive strength,28d compressive strength,etc.The optimum mixing parameters of one-part alkali slag cementitious materials were obtained.Meanwhile,in order to solve the brittleness of the alkali-excited material and improve its flexibility and flexural tensile strength,bamboo fiber was blended in the one-component alkali-excited slag mortar,and the strength development(7d and 28d compressive strength,7d and 28d flexural strength,folding to compressive ratio,7d and 28d splitting tensile strength)of the bamboo fiber-modified onecomponent alkali-excited slag mortar was compared and analyzed under the conditions of different blending amounts and bamboo fiber treatment methods,and The microscopic morphology between bamboo fiber and mortar hydration products under the conditions of different modification methods was observed.Finally,plain cement concrete specimens,onepart alkali slag concrete specimens and bamboo fiber-modified alkali slag concrete specimens were prepared,and the test specimens were comprehensively evaluated in terms of their compatibility,mechanical properties,wear resistance,and economic and environmental analyses to assess the feasibility of bamboo fiber-modified one-part concrete applied to pavement materials,and the research results showed that.(1)The optimal mixing parameters for one-component alkali slag cementitious materials are water-cement ratio 0.4,sodium oxide equivalent 0.06,and 50%sodium carbonate admixture.The most influential factor on the material flowability is the water-cement ratio,and the most influential factor on the material strength development is the sodium carbonate admixture.Under the suitable water-cement ratio condition,the low sodium carbonate admixture can effectively improve the strength development of the slurry,but it will make the slurry flowability worse and intensify the reaction rate.(2)The main hydration products of one-part alkali slag gelling materials are C-(A)-S-H gel,hydrotalcite,and calcite,and some quartz and mullite are also present.The hydration products condensed with each other to form a three-dimensional mesh structure,with dense structure and relatively smooth surface.(3)The admixture of bamboo fiber can effectively improve the fracture resistance of one-part alkali slag mortar and enhance its toughness.The strength of the mortar increases with the amount of bamboo fiber and then decreases,and the optimal amount is 1.5%.The pretreatment of bamboo fiber with alkali solution can effectively improve the bond between bamboo fiber and hydration products,and the 28d compressive strength and flexural strength of the mortar can reach 39.56MPa and 10.21MPa respectively when bamboo fiber is treated with alkali solution and the fiber admixture is 1.5%.(4)Compared with ordinary cement concrete materials,bamboo fiber modified onecomponent alkali slag concrete materials can provide excellent mechanical properties and wear resistance while meeting the construction and ease requirements..