Study on the Basic Performance and Noise Characteristics of Rubber Cement Concrete of Modified Latex

The test is divided into a rubber content of 0%, 5%, 10%, 15% and 20%，under the conditions that the SBR content 5% of cement mass, study the ratio of tension and pressure and fracture pressure performance of latex rubber modified concrete, and studies the noise reduction properties of concrete, test ultrasonic propagation velocity in the concrete. Tests show that rubber latex can improve the interface effect between rubbers and cement base material, improve the bonding strength between the two, improve the ratio of tension and pressure and fracture pressure ratio performance of concrete, and reduce the propagation velocity of ultrasonic in concrete, enhance the noise reduction performance of concrete.

Study on the Properties of Straw Fiber Reinforced Cement-Based Composite

Plant fiber concrete in the cement base material (cement, mortar or concrete) to join the natural plant fiber, to form a new type of concrete, its advantages can improve the performance of concrete, concrete to reduce costs, save energy. Understanding straw fibers mixed with concrete, the variation in performance, with the same concrete than different content, physical and mechanical properties of the different shapes straw fiber concrete test analysis of the concrete compressive strength, splitting the variation of tensile strength, flexural strength, and economic aspects of performance, to provide a reference for further study of the straw fiber reinforced concrete and other performance and application.

The effect of giving NaOCL 2.5% and H2O2% solution on the initial setting Mineral Trioxide Aggregate (MTA)

Today, Mineral Trioxide Aggregate (MTA) is one of the most commonly-used materials to overcome problems in dental pulp as well as periodontal tissue. This substance received its permission from the American Food and Drug Administration (FDA) in 1998 and has been patented as a Portland type I.ASTM C150 cement-base material. However, MTA still has its flaws, such as: its granule form, requirement for moist condition, mass losing during hydration (high solubility), and particularly its time-consuming setting duration (45’-165’). Some researches attempt the usage of regular accelerator together with Portland cement, yet there’s still no certainty of the best concentration that can be used to gain optimal result. This research conducted a time test of the initial setting of MTA that was mixed with the strong-oxidation antimicrobial solutions, they are NaOCl 2.5% dan H2O2 3%. The instrument used was the Gillmore needle. Data analysis used one-way ANOVA and Mann Whitney significance test (p<0,05). The result of the research showed that the mixing of NaOCl 2.5% with MTA the initial setting was ± 11 minutes and the mixing of NaOCl 2.5% with MTA the initial setting was ± 5 minute, it compared with the initial setting of original MTA which was the initial setting ± 50 minutes.