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Mar 22, 2006· This investigation deals with determining the carbonation resistance of high-volume fly ash concrete. Five air-entrained concrete mixtures were studied consisting of three high-volume fly ash concrete mixtures (HVFA) incorporating 58% of fly ash by mass of the total cementitious materials made with a water-cementitious materials ratio …
Apr 01, 2000· The results show that the carbonation of concrete with 15% to 30% fly ash is similar to or slightly higher than equivalent strength concrete without fly ash. Concrete …
Jiang et al. investigated the effect of ZSM-5 (Zeolite Socony Mobil-5) waste dosage on the ... and (b) ordinary, (c) and (d) pressurized , (e) raw material carbonation modification and (f) alkali immersion carbonation concrete test blocks. ... Clinkering-free cementation by fly ash carbonation. J. CO 2 Util., 23 (2018), pp. 117-127 ...
Dec 30, 2020· First, carbonization tests were conducted under different freeze-thaw cycles and fly ash contents; then PS (Photoshop) and IPP (Image-Pro Plus) were adopted to measure the carbonized area and calculate the ratio of carbonized area (RCA). The experimental results showed that, when the fly ash content was between 10% and 30%, …
Mar 17, 2022· FLY ASH IN CEMENT CONCRETE Fly Ash in Cement Concrete Ordinary Portland Cement (OPC) is a product of four principal mineralogical phases. These phases are Tricalcium Silicate-C3S (3Cao.SiO2), Dicalcium Silicate-C2S (2Cao.SiO2), Tricalcium Aluminate-C3A (3CaO.Al2O3) and Tetracalcium alumino-ferrite – C4AF(4CaO.Al2O3 …
Jun 09, 2014· (1) The quality of fly ash is unstable because the quality of fly ash changes greatly with that of coals [11, 12]; (2) there is lower early age compressive strength of concrete due to lower activity of fly ash [13, 14]; (3) pozzolanic reaction of fly ash leads to decreased pH value of concrete, which results in a poor carbonation resistance [15 ...
The experimental results show that replacing Portland cement in concrete with fly ash increases the carbonation rate at early ages, while the late age carbonation rate is …
The present study consists of investigating the carbonation resistance of two series of concrete mixtures designed for three classes of concrete (25, 35, and 45 MPa compressive strength at 28 d) and using American Society for Testing and Materials (ASTM) type I Portland cement and two commercially used fly ashes meeting the ASTM standards at …
Jan 03, 2020· The present study investigates the carbonation resistance of Low Volume Fly Ash (LVFA) and High Volume Fly Ash (HVFA) based Self Compacting Concrete (SCC) made with Coarse Recycled Concrete ...
May 10, 2020· Fig. 11 shows that compared with ordinary concrete, substituting fine aggregate with fly ash can improve the carbonation resistance of concrete; on the 28th …
Apr 01, 2000· The paper presents data for specimens up to ten years of age. The results show that the carbonation of concrete with 15% to 30% fly ash is similar to or slightly higher than equivalent strength concrete without fly ash. Concrete containing 50% fly ash carbonated at a significantly faster rate than control specimens of the same grade and …
Sep 09, 2011· The paper presents an investigation on the influence of the fineness of fly ash on the carbonation and electrical conductivity of concrete. Fly ash collected from three thermal power stations in India (with a Blaine's fineness of 200, 255, and 305 m 2 / kg, respectively) were used for this study.The study also involved three replacement levels …
Nov 11, 2016· The study shows that if fly ash content is limited to 20% of cementitious material and carbonation curing duration is not to exceed 12 h, fly ash concrete can be produced with higher early strength, comparable late strength, better durability performance, and a carbon emission reduction of 36%.
The present study consists of investigating the carbonation resistance of two series of concrete mixtures designed for three classes of concrete (25, 35, and 45 MPa …
Oct 05, 2005· Abstract. The aim of this paper is to develop a model for simulating carbonation of fly ash concrete. The model describes the diffusion of gases ( C O 2 and …
Investigation of the effect of partial replacement of Portland Cement by Fly Ash on carbonation using TGA and SEM-EDS. I: Proceedings of the International RILEM Conference Materials, Systems and Structures in Civil Engineering 2016 Segment on Concrete With Supplementary Cementitious Materials.
Jan 03, 2020· Abstract and Figures. In order to investigate the carbonation resistance of concrete with fly ash as fine aggregate (CFA), the rapid carbonation test was conducted to explore the influence of the ...
Dec 15, 2010· Made available by U.S. Department of Energy Office of Scientific and Technical Information ...
Sep 01, 1992· M. Thomas, J. D. Matthews. Published 1 September 1992. Materials Science, Engineering. SP-192: 2000 Canmet/ACI Conference on Durability of Concrete. The carbonation of fly ash concrete is reported, with particular emphasis on the role of curing. Concretes with nominal strength grades C25, C35 and C45 and a range of fly …
The effects of carbonation on the microstructure of concrete containing fly ash and expansive admixture are investigated in this paper. Eight mix proportions of the concrete are designed in the experiment with the different replacement levels of the Portland cement with the fly ash and the expansive admixture. The specimens cured in accelerated …
This paper presents the carbonation of fly ash concrete investigated with microhardness analysis.After fly ash concrete specimens are exposed in accelerated carbonation environment for 7 d and 28 d,the concrete plate about 50 mm thick is split from the specimen and the cross section is sprayed with phenolphthalein solution to measure …
This paper presents the carbonation of fly ash concrete investigated with microhardness analysis.After fly ash concrete specimens are exposed in accelerated carbonation environment for 7 d and 28 d,the concrete plate about 50 mm thick is split from the …
containing silica fume was more than that in the fly ash concrete without silica fume, and a considerable increase in the dry shrinkage strain of the concrete was observed by increasing the dosage of silica fume. – The presence of silica fume in concrete containing fly ash reduces the carbonation depth considerably.
The effects of carbonation age, fly ash content in the binder and the water to binder ratios on the carbonation depth of fly ash concrete is investigated and the micromechanical properties of the hardened paste and the inter facial transition zone is analyzed with the micro-hardness method. The experimental results show that replacing Portland cement …
Oct 07, 2010· The carbonation resistance of flyash concrete is an issue of some controversy with conflicting results being found in the literature. Based on their data, …
Sep 01, 1992· Carbonation of Fly Ash Concrete. M. Thomas, J. D. Matthews. Published 1 September 1992. Materials Science, Engineering. SP-192: 2000 Canmet/ACI …
Wang et al. investigate the apparent characteristics of reactive MgO-fly ash solidified sludge specimens as the carbonation period extends from 0 h to 24 h (Fig. 9(a)). The specimen surface displays a relatively slight change in a short carbonation period (about 1–2 h), and the transverse cracks appear and develop visibly on the specimen ...
The performance of the fly ash as a calcium source for direct aqueous carbonation at atmospheric pressure was investigated for different solid-liquid ratios and introduced CO2 concentrations.
Today, a rather poor carbonation resistance is being reported for high-volume fly ash (HVFA) binder systems. This conclusion is usually drawn from accelerated carbonation experiments conducted at CO 2 levels that highly exceed the natural atmospheric CO 2 concentration of 0.03–0.04%. However, such accelerated test conditions may change the …
Jun 06, 2021· Alkaline waste materials such as fly ash, waste concrete powder, and steel making slag are also useful resources for mineral carbonation. 15−27 Mineral carbonation using alkaline waste has multiple advantages. In general, the mineralization reaction rates with wastes would be higher than those for rocks.
Jun 15, 2009· Download Citation | Carbonation of fly ash concrete and mircro-hardness analysis | The effects of carbonation age, fly ash content in the binder and the water to binder ratios on the carbonation ...
May 25, 2015· The carbonation of fly ash concrete is reported, with particular emphasis on the role of curing. Concretes with nominal strength grades C25, C35 and C45 and a range of fly ash levels (0–50%) were exposed to various treatments during the first 28 days; i.e. different moist curing periods anda range of ambient temperatures and relative …
Jan 01, 2019· This paper mainly focuses the effect of high incorporation ratios of fly ash (FA) and recycled concrete aggregates (RCA) on the carbonation resistance of concrete. The aim of using high volumes of these non-traditional materials is to decrease the use of natural resources and capture CO 2 .
