Study On Amylopection Modifying Performance Of Building Mortar

As an organic cementing agent, amylopection can be combined with lime, which usually is employed as an inorganic cementing material in building mortar. Calcium carbonate of calcite crystals is formed through organic-inorganic recombination. In this thesis, building mortar modified with amylopection was prepared with lime, clay and sand were main materials, modifying with sticky rice slurry, alums, sodium hydroxide and sodium carbonate. The research works includes the following aspects:(1) Under the certain raw material ratio, concentration of sticky rice slurry, mixing time, liquid-solid ratio, the dosage of alums, sodium hydroxide and sodium carbonate were investigated by single-factor experiments, parameters of different influence factors were initially identified. Besides, effects of curing atmosphere of air and carbon dioxide on the compressive strength were also investigated. The results showed that the compressive strength of samples increased significantly under carbon dioxide curing.(2) Based on single factor experiments, the orthogonal experiment was carried out to obtained the optimum conditions. The parameters were optimized and influences of different preparation factors on the test results were analyzed by direct-vision and variance analysis. It showed that compressive strength and the water stability coefficient were successively influenced by liquid-solid ratio, the concentration of sticky rice slurry and the alums dosage.(3) Properties of samples were measured and characterized, including density, compressive strength, coefficient of water stability and microstructure. The results showed that favorable samples was attained with a ratio of lime, clay and sand of2:5:3, mixing time of30min, the concentration of sticky rice slurry of3%, liquid-solid ratio of0.325, the alums dosage of0.1%. Under the optimization conditions, the density of sample was1576.45kg/m5, the compressive strength was1.235MPa, the water stability coefficient was0.593. The compressive strength of samples increased with increasing of sodium hydroxide and sodium carbonate, while the water stability became deteriorative substantially.The lime mortar modified with amylopection in sticky rice is an organic-inorganic composite material, its compressive strength and water stability is improved through modification. It examines traditional building mortar and provides an environment-friendly, recycled and energy saving materials. The research results have theoretical significance and practical applications.