Compressive Strength and Rapid Chloride Permeability of Concretes with Ground Fly Ash and Slag

2009 ◽  
Vol 21 (9) ◽  
pp. 494-501 ◽  
Author(s):  
Ozkan Sengul ◽  
Mehmet Ali Tasdemir
2020 ◽  
Vol 40 (2) ◽  
Author(s):  
Daniela Eugenia Angulo-Ramírez ◽  
William Gustavo Valencia-Saavedra ◽  
Ruby Mejía de Gutiérrez

Concretes based on alkaliactivated binders have attracted considerable attention as new alternative construction materials, which can substitute Portland Cement (OPC) in several applications. These binders are obtained through the chemical reaction between an alkaline activator and reactive aluminosilicate materials, also named precursors. Commonly used precursors are fly ash (FA), blast furnace slag (GBFS), and metakaolin. The present study evaluated properties such as compressive strength, rate of water absorption (sorptivity), and chloride permeability in two types of alkaliactivated concretes (AAC): FA/GBFS 80/20 and GBFS/OPC 80/20. OPC and GBFS/OPC* concretes without alkaliactivation were used as reference materials. The highest compressive strength was observed in the FA/GBFS concrete, which reported 26,1% greater strength compared to OPC concrete after 28 days of curing. The compressive strength of alkaliactivated FA/GBFS 80/20 and GBFS/OPC 80/20 was 61 MPa and 42 MPa at 360 days of curing, respectively. These AAC showed low permeability to the chloride ion and a reduced water absorption. It is concluded that these materials have suitable properties for various applications in the construction sector.


2019 ◽  
Vol 8 (4) ◽  
pp. 8831-8836

This paper discusses on Rapid Chloride Permeability Test investigations on penetration of chloride ions included with replacement of cement by flyash material. By weigth of cement, the fly ash content is replaced from 0% to 60%. Concrete mixes with different binder content varies from 350, 400 and 450 kg/m3 were proportioned with different water binder(w/b) ratios = 0.4, 0.45 and 0.50. Specimens were casted and tested for 28 days. For all the combinations, RCPT was carried out and the charge passed through the specimens was noted. Rapid Chloride Permeability Test value of concrete without fly ash was found to be more than the concrete with fly ash. The Rapid Chloride Permeability Test values are found to be decreased if the percentage of flyash increases. The reason could be the pozzolanic reaction products (CSH) fill the pores between the cement pastes and cause a denser concrete matrix, resulting in better durability. Hence, it can be suggested that the fly ash concrete up to 50% replacement can be used for variety of applications.


Materials ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2291 ◽  
Author(s):  
Nasir Shafiq ◽  
Rabinder Kumar ◽  
Muhammad Zahid ◽  
Rana Faisal Tufail

This paper discussed the effects of modified metakaolin (MK) with nano-silica (NS) on the mechanical properties and durability of concrete. In the first phase, trial mixes of concrete were prepared for achieving the desired value of the 28 days compressive strength, and the charge passed in rapid chloride permeability test (RCPT). In the second phase, statistical analysis was performed on the experimental results using the response surface method (RSM). The RSM was applied for optimizing the mix proportions for the required performance by exploiting the relationship between the mix characteristics and the corresponding test results. A blend of 10% MK + 1% NS as part of cement replacement exhibited the highest mechanical properties and durability characteristics of concrete; concrete mix showed that the 28-days compressive strength (CS) was 103 MPa, which was 15% greater than the CS of the control mix without MK or NS. The same mix showed more than 40% higher flexural and split-tensile strength than the control mix; also it resulted in a reduction of 73% in the rapid chloride permeability value. ANOVA technique was used for optimizing the nano-silica and metakaolin content for achieving maximum compressive strength and minimum RCPT value. Statistical analysis using ANOVA technique showed that the maximum compressive strength and lowest RCPT value could be achieved with a blend of 10% MK and 1.55% NS.


2018 ◽  
Vol 9 (1) ◽  
Author(s):  
Amir Fauzi ◽  
Syukri Syukri ◽  
Mulizar Mulizar ◽  
Muhammad Reza

Abstract — Industrial waste products can be considered as renewable resources, one of them is a steel manufacturing, which produced dust waste contain sponge iron, scrap metal and other steel wastes that impacted to environment. This waste material was called Electric Arc Furnace Dust (EAFD). This study investigates the feasibility of using EAFD as a cement replacement compared to silica fume (SF) and fly ash (FA) in terms of Chemical composition, workability, setting time, compressive strength and rapid chloride permeability resistance. The results showed that workability of EAFD is almost similar to control even if percentage of EAFD was increased. It is not refer to FA more workable or SF less workable with increase percentage of replacement. Furthermore, the EAFD significantly affect the setting time, which 3% EAFD replacement bring to prolong final setting time to more than 24 hours, while the setting time of SF and FA did not significant affected along with the increase replacement percentage. In addition, the 3% EAFD is optimum replacement for compressive strength and it is equivalent replacement level to 5% SF and 15% FA. Finally, the EAFD enhance the resistance for rapid chloride permeability more than FA but less than SF.


2020 ◽  
Vol 71 (7) ◽  
pp. 775-788
Author(s):  
Quyet Truong Van ◽  
Sang Nguyen Thanh

The utilisation of supplementary cementitious materials (SCMs) is widespread in the concrete industry because of the performance benefits and economic. Ground granulated blast furnace slag (GGBFS) and fly ash (FA) have been used as the SCMs in concrete for reducing the weight of cement and improving durability properties. In this study, GGBFS at different cement replacement ratios of 0%, 20%, 40% and 60% by weight were used in fine-grained concrete. The ternary binders containing GGBFS and FA at cement replacement ratio of 60% by weight have also evaluated. Flexural and compressive strength test, rapid chloride permeability test and under-water abrasion test were performed. Experimental results show that the increase in concrete strength with GGBFS contents from 20% to 40% but at a higher period of maturity (56 days and more). The chloride permeability the under-water abrasion reduced with the increasing cement replacement by GGBFS or a combination of GGBFS and FA


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