بررسي خصوصيات بتن خودمتراكم پليمري

Experimental Study of Polymer Self-Compacting Concrete

در اين نوشتار به بررسي خصوصيات بتن خودمتراكم پليمري به همراه رزين سنگ مصنوعي كه در دو محيط آب و سولفات منيزيم نگهداري شده‌اند، پرداخته ‌شده است. براي اين منظور 15 طرح اختلاط مختلف ساخته و در سولفات منيزيم و آب نگهداري شده است. پليمر مورد استفاده آلژينات داشته است، كه در دندان‌پزشكي كاربرد دارد. در اين مطالعه نمونه ها در 3 فاز ساخته شده‌اند. فاز اول شامل نمونه هاي با 1? رزين، فاز دوم با 5/1? رزين و فاز سوم با 2? رزين است. در تمامي فازها از آلژينات با درصدهاي 5/0، 1، 5/1، و 2 استفاده شده است. مقاومت فشاري و خمشي، و جذب آب نمونه‌ها در سنين مختلف اندازه‌گيري شده است. نتايج پژوهش نشان داده است كه استفاده از 5/0? آلژينات و 2? رزين، مقاومت فشاري بتن را در محيط سولفات حدود 25? افزايش داده است. همچنين استفاده از 2? آلژينات و 2? رزين، مقاومت خمشي نمونه‌ي عمل‌آوري‌شده در محيط سولفات را 67? افزايش و جذب آب را كاهش داده است.

This paper presents an experimental study on the properties of self-compacting concrete (SCC) using natural polymer (SCC). Fifteen series of mixed proportions were used, which were cured in two environments of magnesium sulphate and by water curing. The polymer used is alginate, which is used a lot in the dentistry industry. It is used extensively as an impression making material in dentistry, prosthetics, life casting and occasionally for creating positives for small scale casting. In addition, alginate is used in the food industry, engineering and construction. This polymer is made in a variety of percentages: 0.5, 1, 1.5 and 2, with different percentages: 1, 1.5 and 2, of resin. The values of w/c in all samples are 0.36. The objective of this study is to investigate the influence of alginate on the fresh, hardened and sulphate resistance properties of SCC. The performance of alginate is established in SCC using fresh concrete tests, such as slump flow, T500 time, J ring and L-box ratio, and by hardened concrete tests, such as compressive strength, flexural strength, water absorption and density in magnesium sulphate solutions. The compressive strength and density of each mix design, over 7, 28, 56, and 90 days, are determined. In addition, prismatic specimens are made to determine the flexural strength at 28 days of curing. Two cubic specimens are made to determine water absorption at 28 days of curing. The results of the fresh concrete show that increasing alginate content negatively affected the blocking ratio, because of viscosity decrease. This reduction is because of diatomaceous earth. The use of alginate increases the strength of the sulphate solutions. The highest flexural strength value is seen in the R1.5A1 sample in the sulphate environment. The R1A1 has the least density compared with other samples. The R2A1.5 sample has a higher compressive strength, over 56 and 90 days, in the sulphate environment rather than the water environment. Results show compressive and flexural strength in upper ages. The R2A2 has the least water absorption compared to the other samples.