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Utilization of high strength and high performance concrete as a superior material in the third millennium has become an easy matter and has always been considered by researchers, designers and contractors, although the mechanical properties of the structural members made of this kind of concrete is not completely known in detail. The purpose of thi...
Context in source publication
Context 1
... it is observed in Table 4, the proportion of bending strength to compressive strength of concrete and the proportion of tensile strength to compressive strength decreases with increasing of compressive strength. Figure 5 shows the stress-strain curves for HSC and NSC specimens. Modules of elasticity increases with increasing of compressive strength. ...
Citations
... Curing should be started immediately after the concrete is compacted to protect concrete from harmful factors. Concrete curing consists of care and protection or cultivation based on Iran Aba Concrete Regulation (Alizadeh et al., 2005;Bidsardareh & Mohammadi, 2018). Today, modeling using fuzzy logic has found a special place in technical and engineering sciences. ...
Nowadays, concrete is one of the most widely used building materials around the world. The requirement and wide application of concrete have made it necessary to investigate its behavior and the factors affecting its behavior. In the process of concrete production, more precision is necessary to fulfill the requirements of efficiency and strength. In estimating the behavior of concrete, various mathematical techniques have been presented by researchers, and as a result, the theory of fuzzy sets provides a very effective tool for modeling and analyzing vague and imprecise concepts. The present research aims to predict the 28-day strength of concrete based on the 7-day strength in the presence and absence of zeolite pozzolan models with different curing methods in water, sack, and plastic using fuzzy logic. One of the novel aspects of this study is that it uses fuzzy logic to analyze lab data. This is because fuzzy logic can be used to analyze data even when there is uncertainty. Thus, 12 mixing designs have been prepared to check the grade of cement on the researched parameters based on the values of 300, 400, and 500 kg/m3 containing zeolite in the amounts of 0, 5, 10, and 15 weight percent of cement. All samples have been subjected to tests of concrete performance (slump test) and hardened concrete (compressive strength) at the age of 28 days. After completing the tests, the 28-day compressive strength of concretes has been predicted using fuzzy logic. This study shows that fuzzy logic can be applied as a powerful tool for modeling the compressive strength
of concrete.
In this study, the compressive strength of the concretes made by the pipeline water of Larestan has been investigated. Although the used water for the concretes must be clean, standard, and generally drinkable water, in Larestan city, the pipeline water is nonpotable water; meanwhile, this type of water is still being used in the mixture of the concretes by companies and contractors. Since in the initial tests the compressive strength of the normal samples did not satisfy the standards, 50% of granite aggregate was replaced with the purpose of increasing strength of the samples. Then four types of samples were made, which are (1) normal concrete with pipeline water, (2) normal concrete with potable water, (3) granite concrete with pipeline water, and (4) granite concrete with potable water. The results showed that the compressive strength of normal samples is not standard in the case of using the pipeline water. This issue can be seen during the first four weeks of the samples, whereas these samples are placed in the standard zone by replacing 50% of granite aggregate instead of normal aggregates. This may be attributed to the compensating effect of granite aggregates in opposition to damaging effect of water. Also, by using the granite aggregates in the mixture, the compressive strengths of the samples were standard and almost identical in both cases of pipeline water and tap water. As a result, the concretes made in this city must include additives for increasing the strength, or the tap water should be used as a replacement for pipeline water.
