Technology to improve the quality of asbestos-cement roofing sheets by using a mixture of additives from industrial waste sources to replace cement

Abstract

The article presents the results of laboratory and industrial tests of asbestos-cement sheets produced with a reduced amount of cement by 20, 50%, which was replaced by complex mineral additives. The test results have been compared the physical and technical parameters of the resulting product with ordinary market products manufactured in both Vietnam and Russia. The aim of the research was to test the theory of the possibility of replacing cement in asbestos-cement sheets with complex mineral additives without losing the quality of the final products.In the laboratory conditions, several series of samples were produced with different ratiocomplex mineral additives to cement from 20% to 50%. All the samples were later tested at Vietnamese Institure for Building Materials (VIBM) laboratories. After obtaining positive laboratory results, industrial tests were carried out at one of the factories in Vietnam. In production conditions, without stopping the machine and without changing its parameters, 20% of the cement has been replaced with mineral powder in five consecutive mixtures. The physical and mechanical properties of all samples of asbestos-cement sheets with different amounts of complex mineral additives exceed those of the control asbestos-cement sheets. The exceeding strength of samples with a complex mineral additive relative to the strength of control samples was from 8.5% to 41.3% on curing eighth days and from 3.4% to 31.4% on curingfourteenth days. The true density of samples with a complex additive is also higher than that of control samples. The theory of replacing a part of the cement with complex mineral additives in the production of asbestos-cement sheets has been experimentally tested. In real production conditions, when 20% of cement is replaced by a complex additive, all physical and mechanical products of the manufactured products exceed the control samples. This opens up the possibility of further reducing the amount of cement without losing product quality and without increasing the amount of asbestos fiber. It shall bring a significant reduction in production costs will be achieved.