Influence Of Surface Additives On Strength Indicators Of Cement Systems

Аннотация

In the state predostavlena, v issledovaniy yavilos ustanovlennыe vliyaniya dobavok poverxnostno - aktivnyx veshchestv na prochnostnыe pokazateli tsementnyx sistem. Definitions were made on cement of various mineralogical composition, svejemolotom and lejalom and on tsementno- peschannyx solutions and betonax. KEYWORDS Additives, cement, water-cement ratio, freshly ground, cement-sand mortars and concretes. INTRODUCTION The ultimate strength in compression, bending and elastic modulus were determined The purpose of the research in this section for mortar samples on beams 4x4x16 cm and was to establish the effect of surfactant cubes 7.07x 7.07x 7.07 cm, and for concretes additives on the strength characteristics of on cubes 10x10x10cm and 20x 20x20cm. It is cement systems. The determinations were known that in a number of cases when using carried out on cements of various mylonft there is some lack of strength at the mineralogical composition, freshly ground and initial stage. A decrease in the strength of buried, and on cement-sand mortars and products on hydrophobic cements was concretes. observed only on freshly ground cements For the control samples and with additives, when molding samples with a high water- the same plasticity was selected, while the cement ratio. Therefore, a large number of water-cement ratio than for various additives comparative tests of the strength of samples fluctuated within certain limits. on hydrophobic-plasticized and control The US A Journals Volume 02 Issue 12-2020 81 The American Journal of Applied Sciences IMPACT FACTOR (ISSN – 2689-0992) 2020: 5. 276 Published: December 27, 2020 | Pages: 81-85 Doi: https://doi.org/10.37547/tajas/Volume02Issue12-13 OCLC - 1121105553 cements were carried out. The tables below introduction of oxidized petrolatum in an show the results of these tests. amount of 0.25% increased the plasticity of the solutions (increasing the value of the slump of Table reduced to the results of tests of the cone), did not reduce the strength ordinary cement parameters even with water-cement ratios the (I-B and I D and cement with a high content of same as those adopted for the control C3C (3-C and 5-I). compositions. As follows from the data in the table, cement The results of testing solutions on slag mortars with OP with a decrease in the water- Portland cements and clinker cements are cement ratio (with different plasticity) are given in table. Cement consumption in characterized by increased compressive and solutions with oxidized petrolatum decreased flexural strengths in comparison with the slightly in comparison with the control. control indicators at all test periods up to a Samples were subjected to normal air and year. In this case, the optimal dosage of OP is water storage. As follows from the data in the range of 0.15-0.30%, the strength of the carried out, in most cases the addition of samples on such cement samples increases by oxidized petrolatum increased the strength of 10-12% compared to the control. the solutions in comparison with the control. The combined addition of oxidized petrolatum Mortars with OP additives, made at the same and SNV somewhat lowers the strength of water-cement ratio as the control ones, are solutions at all test periods. Particularly characterized by a shortage of strength interesting results were obtained when (about 5%) in the initial hardening period (3 testing samples of air storage. days) and equalization of the strength values to 28-day hardening (cement ID). Samples of the composition 1: 6 on Portland cement with oxidized petrolatum showed The addition of mylonft, in spite of a decrease strength at 3 days of age by 57%, at 7 days of in the water-cement ratio, in some cases yields age at 100.28 days at 59 and 90 days of age, a 5-8% shortfall in strength compared to the 62% higher than that of the samples on the control ones even after 360 days of control cement. The significant difference in hardening. The greatest increase in strength is strength between rigid control compositions achieved when using a synthetic fatty acid of and compositions with OP additives is the C7-C9 fraction. The introduction of this explained by the difference in fluid loss rate, additive increases the strength of samples at 3 i.e. in the rate of drying, samples during air days of age by 50%, at 28 days of age by 35% storage. The increased water retention and 360 days of age - by 25%. capacity of solutions with OP additives provides a more intensive set of strength of Table the results of tests of laboratory-salted solutions under conditions of air storage. This cements and solutions based on these property of cements with surfactant additives cements are presented. The addition of is especially important for hydraulic oxidized petrolatum causes in all cases an engineering. increase in the strength of the cement and when tested at 3,7 and 28 days of age, despite Table the results of physical and mechanical the increase in the normal den