RPC130活性粉末混凝土配合比设计与应用研究
发布时间：2019-06-01 22:15
【摘要】：活性粉末混凝土(Reactive Powder Concrete简称RPC),是一种新型的超高性能的水泥基复合材料,它是由水泥、级配石英细砂、石英粉、硅灰、超塑化剂和钢纤维等组成,在凝结、硬化过程中可采取适当的成型养护工艺,如加压、加热而获得。与普通混凝土相比RPC具有高强度、高韧性、高耐久性、体积稳定性良好等优点,但RPC中的石英砂、硅灰、钢纤维都是价格昂贵的材料,其中钢纤维价格占整个RPC造价的50%左右,在当前技术领域仍未找到一种更为廉价的纤维材料代替钢纤维。因此,在RPC配合比设计过程中,优化配合比设计,最大限度地减少钢纤维用量是降低RPC成本的有效途径,对RPC的推广及应用有着十分重要的意义。 本文试验研究了RPC力学性能的影响因素,其中包括水胶比、硅灰掺量、硅灰品质、硅灰状态、粉煤灰和矿粉掺量、钢纤维掺量、石英砂级配等,当胶凝材料为水泥、矿粉、硅灰,最低钢纤维体积掺量为1.2%,石英砂级配采用粗、中、细三种级配,外加剂为胶凝材料的2%时,成功配制出力学性能满足要求的RPC,其中配制出的RPC抗压强度可达到142.3MPa,抗折强度可达到19.0MPa.弹性模量可达到49.0GPa。 本文还通过电通量法、快速冻融法研究了RPC的抗氯离子渗透和抗冻融破坏的能力。试验结果表明：当矿粉替代水泥用量15%,钢纤维体积掺量为1.2%时,6h通过此RPC试件的电量为25.7C,600次冻融循环后RPC的质量损失4.0%,相对动弹性模量为74.6%,低于标准中关于试件的质量损失率达到5%或相对动弹性模量下降至60%以下的要求,说明该配比配制出的RPC具有优异的抗渗性和抗冻性。确定最终配合比为水泥：矿粉：硅灰：石英砂：钢纤维=1：0.18：0.29：1.53：0.15,水胶比为0.175,减水剂为胶凝材料的2.0%。 本文通过进一步的微观试验,进行RPC具有高强度、高耐久性的机理分析。试验表明：RPC密实度高,内部缺陷少,孔隙率低,易腐蚀的组分含量低等特点,使得RPC具有较高的强度和耐久性。 除了RPC性能满足要求,本问还针对RPC在实际生产过程中遇到的下料口堵塞分料机,盖板表面有白色痕迹和垫块痕迹,色差不均,钢纤维在表面显现等问题进行分析研究,通过调试生产设备、改进生产工艺、调整生产配合比等方法,使得RPC的生产能够顺利进行。
[Abstract]:Reactive powder concrete (Reactive Powder Concrete) is a new type of ultra-high performance cement-based composites, which is composed of cement, graded quartz fine sand, quartz powder, silica fume, superplasticizer and steel fiber. Appropriate molding and curing process, such as pressure and heating, can be adopted in the hardening process. Compared with ordinary concrete, RPC has the advantages of high strength, high toughness, high durability and good volume stability, but quartz sand, silica fume and steel fiber in RPC are all expensive materials. The price of steel fiber accounts for about 50% of the total cost of RPC, and no cheaper fiber material has been found to replace steel fiber in the current technical field. Therefore, in the process of RPC mix proportion design, optimizing the mix proportion design and minimizing the amount of steel fiber is an effective way to reduce the cost of RPC, which is of great significance to the promotion and application of RPC. In this paper, the influencing factors of mechanical properties of RPC are studied, including water-binder ratio, silica fume content, silica fume quality, silica fume state, fly ash and mineral powder content, steel fiber content, quartz sand gradation, etc., when the cementitious material is cement and mineral powder, When the minimum volume content of steel fiber is 1.2%, the quartz sand gradation is coarse, medium and fine, and the admixture is 2% of the cementitious material, the RPC, with mechanical properties satisfying the requirements is successfully prepared with silica fume, the lowest volume content of steel fiber is 1.2%, the quartz sand gradation is coarse, medium and fine, and the admixture is 2% of the cementitious material. The compressive strength and bending strength of RPC can reach 142.3 MPA and 19.0 MPA respectively. The elastic modulus can reach 49.0 GPA. The ability of RPC to resist chloride ion penetration and freeze-thaw damage was also studied by electroflux method and rapid freeze-thaw method. The experimental results show that when the content of mineral powder instead of cement is 15% and the volume content of steel fiber is 1.2%, the electric quantity of the RPC specimen is 25.7C at 6 h, and the mass loss of RPC is 4.0% after 600 freeze-thaw cycles. The relative dynamic elastic modulus is 74.6%, which is lower than the requirement that the mass loss rate of the specimen is 5% or the relative dynamic elastic modulus is reduced to less than 60%. It is shown that the RPC prepared by this ratio has excellent impermeability and frost resistance. It is determined that the final mixture ratio is cement: mineral powder: silica fume: quartz sand: steel fiber = 1 鈮，
本文编号：2490627
[Abstract]:Reactive powder concrete (Reactive Powder Concrete) is a new type of ultra-high performance cement-based composites, which is composed of cement, graded quartz fine sand, quartz powder, silica fume, superplasticizer and steel fiber. Appropriate molding and curing process, such as pressure and heating, can be adopted in the hardening process. Compared with ordinary concrete, RPC has the advantages of high strength, high toughness, high durability and good volume stability, but quartz sand, silica fume and steel fiber in RPC are all expensive materials. The price of steel fiber accounts for about 50% of the total cost of RPC, and no cheaper fiber material has been found to replace steel fiber in the current technical field. Therefore, in the process of RPC mix proportion design, optimizing the mix proportion design and minimizing the amount of steel fiber is an effective way to reduce the cost of RPC, which is of great significance to the promotion and application of RPC. In this paper, the influencing factors of mechanical properties of RPC are studied, including water-binder ratio, silica fume content, silica fume quality, silica fume state, fly ash and mineral powder content, steel fiber content, quartz sand gradation, etc., when the cementitious material is cement and mineral powder, When the minimum volume content of steel fiber is 1.2%, the quartz sand gradation is coarse, medium and fine, and the admixture is 2% of the cementitious material, the RPC, with mechanical properties satisfying the requirements is successfully prepared with silica fume, the lowest volume content of steel fiber is 1.2%, the quartz sand gradation is coarse, medium and fine, and the admixture is 2% of the cementitious material. The compressive strength and bending strength of RPC can reach 142.3 MPA and 19.0 MPA respectively. The elastic modulus can reach 49.0 GPA. The ability of RPC to resist chloride ion penetration and freeze-thaw damage was also studied by electroflux method and rapid freeze-thaw method. The experimental results show that when the content of mineral powder instead of cement is 15% and the volume content of steel fiber is 1.2%, the electric quantity of the RPC specimen is 25.7C at 6 h, and the mass loss of RPC is 4.0% after 600 freeze-thaw cycles. The relative dynamic elastic modulus is 74.6%, which is lower than the requirement that the mass loss rate of the specimen is 5% or the relative dynamic elastic modulus is reduced to less than 60%. It is shown that the RPC prepared by this ratio has excellent impermeability and frost resistance. It is determined that the final mixture ratio is cement: mineral powder: silica fume: quartz sand: steel fiber = 1 鈮，
本文编号：2490627
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