Using fly ash in concrete reduces cracking, permeability, and bleeding, creating a dense, high-durability concrete that is resistant to sulphates and alkali-aggregate reactions. This concrete mix also requires less water and has a tendency to resist shrinking. However, using fly ash in concrete does come with potential problems.
This paper presents research on the impact of fly ash addition on selected physical and mechanical parameters of concrete made with slag cement. Experimental tests were carried out to measure the migration of chloride ions in concrete, the tightness of concrete exposed to water under pressure, and the compressive strength and tensile …
These studies show that the rheological behaviour is affected by external (e.g. temperature and time) and internal (e.g. cement content, the addition of slag, fly ash or superplasticizers, water type and content) factors.
AAFS concretes with different slag content, w/b, Na 2 O content and sand-aggregate ratio were prepared. Table 2 presents the mixture design of AAFS concretes, which were denoted as: slag% (SL), w/b (W), Na 2 O% (N) and sand-aggregate ratio (S). Na 2 O content was designed as low as possible with the consideration of concrete …
According to Portland blast furnace slag Cement, Portland Pozzolana Cement, and Portland fly-ash Cement (GB1344-1999), the national standard, the content of magnesium oxide in clinker should not exceed 5.0%. If the stability of cement tested by autoclave method is qualified, the content of magnesium oxide can be extended to 6.0%.
Using the hydration model and the stoichiometry of the fly ash and slag reaction proposed by Maekawa [10], [11], [12], the amounts of calcium hydroxide, chemically bound water, and capillary water in cement–fly ash blends and cement–slag blends during hydration can be determined with the following equations: (11-1) C H = …
The instability of magnesium phosphate cement (MPC) in moist environments limits its application. In the work reported in this paper, the residual strength and length evolution of MPCs under various curing conditions were investigated to assess the effect of steel slag and fly ash on the stability of MPC. The microstructure of …
Fly ash: the use of low calcium fly ash (CSA Class F and Cl with CaO content < 20%) increases resistance to sulphate atta ck. Fly ashes with more than 20% CaO should be investigated for...
Fly ash reduces the depth of penetration of water under pressure into concrete based on CEM IIIA 32.5 slag cement, to a greater extent than that based on …
Portland cement (PC), a newly released commercially manufactured cement called Minecem (MC) and fly ash (FA) were used as the binders added to the mine tailing materials. Various amounts of two different water types were added to the mixtures in the preparation of backfill material slurry.
Fly ash is the fine ash produced at coal-fired power plants that develops cementitious properties when mixed with cement and water. Fly ash in concrete is widely used across the U.S. to the strength of concrete. Fly ash suppliers such as Cemex use it to improve workability of fresh concrete and reduce water demand, shrinkage and permeability of ...
When the slag content is increased to 1.8, the EMI SE reduces to the lowest value out of the three mixes. Other two mixes with W/C ratios of 0.4 and 0.5 both show that the EMI SE is lowest when the slag content is increased to 1.8. The SE of mix with a W/C ratio of 0.4 and slag content of 1.2 and 1.5 show near-identical behaviour.
Effect of Ultrafine Fly Ash and Water Glass Content on the Performance of Phosphorus Slag-Based Geopolymer. ... Fang G., Ho W.K., Tu W., Zhang M. Workability and mechanical properties of alkali-activated fly ash-slag concrete cured at ambient temperature. Constr. Build. Mater. 2018; 172:476–487. doi: …
Although slag and fly ash cement concrete are characterized as brittle composite materials, slag and fly ash exhibit a slower reaction rate in concrete compared to cement clinkers [11]. Consequently, a significant portion of slag and fly ash remains unreacted in the mixture for a long time period of time [11].
The chemical compositions of the undisturbed phosphogypsum and carbide slag provided by Hubei Tianxin Building Materials Co., Ltd., and the natural gypsum and Portland cement clinker provided by Huaxin Yidu Cement Co., Ltd., are listed in Table 1.The chemical composition of the CFB fly ash provided by Shanxi Datuhe coal-fired …
Portland cement (P.I. 52.5) with a specific surface area of 336 m 2 /kg was used in this study. Class F Fly ash and S95 slag (or grade 100 for ASTM C989) in accordance with the standard GB/T18046-2000 were employed.The chemical compositions of the Portland cement, fly ash and slag are shown in Table 1.In accordance with …
River-dredged sludge has a high water content and minimal bearing capacity and strength. Adding cement, fly ash, and slag to dredged sludge as a …
The paper deals with developing fly ash–Blast Furnace Slag (BFS) composite with additives like cement to utilize waste material in engineering applications.
The findings indicate that the aluminosilicate fractions present in both ultrafine fly ash and ultrafine slag participate in the acid–base reaction of the MKPC …
This study investigated the influences of ultrafine fly ash (UFA) and ultrafine slag powder (USL) on the compressive strengths, autogenous shrinkage, phase assemblage, and microstructure of magnesium potassium phosphate cement (MKPC). The findings indicate that the aluminosilicate fractions present in both ultrafine fly ash and …
Mica schist weathered soil possesses a number of poor engineering characteristics, which make it difficult to use as a subgrade material for resource utilization. Therefore, in this study, a new type of curing agent, CFSD (cement–fly ash–slag–desulfurized gypsum), is proposed for this soil. The effects of different curing …
Only the film water influences the fluidity of the mortar, and the thicker the film, the more fluid the mortar will be. In our opinion, when the content of solids and water in the mortar with fly ash or fine ground slag replacement of cement is kept constant, there will be additional film water in the mix, which is termed free water. Under the ...
silica fume gave the smallest value of 12 mm water penetration. This ratio gave a reduction in permeability of 56% and an increase in compressive strength of 32%. 4. The ratio of 20% replacement of cement weight of fly ash gave the smallest value of 14 mm water penetration for high slag cement.
Fly ash concrete can perform better against chloride, sulfate and acid attacks and can improve corrosion resistance. ... The use of 30 % class F FA in concrete with Ferronickel slag (FNS) as a sand replacement caused a reduction in CS. ... SCC showed increased water permeability as FA content increased (Turk et al., 2013, …
The test results showed that the water-cement ratio, steel slag, and fly ash content have significant effects on the compressive strength and water permeability of the permeable brick. Considering the compressive strength and water permeability, the best mix proportion of permeable bricks was 6.5% for steel slag, 30% for fly ash, and …
Carbon content variability in fly ash is one of the major causes of fluctuating air con-tents. Slag cement does not contain carbon and does not cause instability in the entrained air content. Time of Set. Time of initial set is influ-enced by the use of slag cement and fly ash. Concrete made with slag cement can have faster set times than ...
Fly ash can be used in an effective way to treat domestic wastewater with simple techniques and low-cost adsorbents (Akar, 2010, Aljerf, 2018a, Aljerf, 2018b). …
Every year, a large amount of solid waste such as fly ash and slag is generated worldwide. If these solid wastes are used in concrete mixes to make concrete, it can effectively save resources and protect the environment. The compressive strength of concrete is an essential indicator for testing its quality, and its prediction is affected by …
The water-to-binder ratio varied between 0.30 and 0.58. In total, 39 mixes of specimens were prepared in this study to examine the effects of content, fly ash, slag powder, silica fume and water-to-binder ratios on the properties of ed concrete specimens. The detailed mix proportions for the 39 specimens are tabulated in Table 3.
Slag cement is hydraulic and can be added to cement as an SCM. Silica fume, also called condensed silica fume or microsilica, is a finely divided residue resulting from the production of elemental silicon or ferro-silicon alloys that is carried from the furnace by the exhaust gases. Silica fume, with or without fly ash or slag, is often used to ...
In addition, in Table 6, Mix1 with 30 MPa and Mix2 with 40 MPa both have the same cement and water content, but the slag content of Mix2 is much higher than that of Mix1. The binder in concrete consists of cement, fly ash, and slag. As Mix2 has a higher binder content, the water–to–binder ratio of Mix2 is lower than that of Mix1.
Silica reacts with lime from cement to produce strength and reduce permeability (class F fly ash should have 50 percent silica content; class C should have 35 percent silica content). Ask that the water requirement be less than the control, that the color, density and fineness have a minimum variation (<5 percent) and that the strength …
@article{Zhao2020EffectsOW, title={Effects of water content, water type and temperature on the rheological behaviour of slag-cement and fly ash-cement paste backfill}, author={Yue Zhao and Abbas Taheri and Murat Karakus and Zhongwei Chen and An Deng}, journal={International journal of mining science and technology}, year={2020}, …
The increase in flowability of concrete mixtures made with high content of slag and fly ash is attributed to the fact spherical shape of fly ash and slag particles, which enhance concrete flow. Table 3 also shows that although it was feasible to develop high flowable concrete with w/c of 0.37, such concrete exhibits very low deformability …
In this study, the densities of water, cement, slag, fly ash, sand, coarse aggregate, and . ... cement and water content, but the slag content of Mi x2 is mu ch higher than tha t of Mix1.
S95-Grade slag and Class-F fly ash sourced from Gongyi Longze Water Purification Material Co., Ltd. (Henan province, China) were used as the main aluminosilicate-rich precursor of geopolymer. The specific surface areas of cement, slag, and fly ash used are 342, 505, and 935 m 2 /kg, respectively.
Use of Municipal Solid Waste Incinerator (MSWI) Fly Ash in Alkali Activated Slag Cement Download book PDF. Download book EPUB ... Therefore, at the mass content of MFA was 30%, the best water/binder ratio and activator solution content was 4% and 6%. When these pastes were cured at 23 °C for 3, 7 and 28d, the …
Different slag and fly ash proportions are studied at two different solution-to-binder (S/B) ratios. Alkali solutions are made with 5 M NaOH and water glass to have a final silica modulus of 1.28.
The fluidity of all ed concrete with different contents of s, fly ash, slag powder, silica fume and varied water-to-binder ratio is presented in Fig. 5(a)-(e). From Fig. 5(a), it can be seen that the fluidity of the tested ed concrete specimens increased gradually as the content increased, with the highest fluidity of 232 mm ...
Fly ash is a by-product from the combustion of pulverized coal, and is widely used as an ingredient in hydraulic-cement concrete. Because it improves many desirable properties of concrete, it is introduced either as a separately batched material or as a component of blended cement. Fly ash reacts with the hydrating hydraulic cement to …
