scholarly journals Compressive Strength of Mortar with Partial Replacement of Cement by Fly Ash and GGBFS.

2021 ◽  
Vol 14 (4) ◽  
pp. 146-155
Author(s):  
Safie Safie Mahdi Oleiwi

The compressive strength characteristics of mortar containing Ground Granulated Blast Furnace Slag (GGBFS) and Fly Ash (FA) in mortar by partial substitution of cement are investigated in this work. The increased demand for cement in the construction industry is a concern for environmental degradation; in this case, waste materials such as GGBFS and FA are used to replace cement. The optimal level of GGBFS and FA was determined using a percentage range of 0% to 40% for different curing days. Compressive strength tests were performed on the replaced mortar. For all mixes, the binder-to-water ratio was kept at 0.4. The compressive strength tests were conducted for 7, 28 and 90 days of curing on a Mortar. The result obtained that as the curing time increased the compressive strength of mortar containing GGBFS and FA increased. In comparison to M1 (cement only), the compressive strength improved by 13.15 percent and 15.5 percent at M3 (20%FA) and M8 (30%GGBFS), respectively. The results showed that adding GGBFS and FA to mortar improve compressive strength, which is improves the mechanical properties of the mortar.

2019 ◽  
Vol 5 (4) ◽  
pp. 913-921 ◽  
Author(s):  
Azmat Ali Phul ◽  
Muhammad Jaffar Memon ◽  
Syed Naveed Raza Shah ◽  
Abdul Razzaque Sandhu

This paper investigates the compressive strength properties of concrete with Ground Granulated Blast Furnace Slag (GGBS) and Fly Ash in concrete by partial replacement of cement. The incremental demand of cement in the construction field is a concern for environmental degradation, in this regard; replacement of cement is carried out with waste materials by using GGBS and Fly Ash. On optimum level of GGBS and Fly Ash was assessed with varied percentage from 0 to 30% for different curing days. Replaced concrete were tested with the slump, compaction factor, Vee-bee and compressive strength. Cement to water ratio was maintained at 0.47 for all mixes. The compressive strength tests were conducted for 3, 7, 14 and 28 days of curing on a M25 grade concrete. The results obtained from the slump, compaction factor, Vee-bee and compressive strength of concrete containing GGBS and Fly Ash was increased as the curing time increases. The workability of replaced concrete improved when slump value achieved 30% as compared to controlled one SF0 and the compressive strength obtained 26.30% improvement at SF9 as compared to SF0. The outcomes indicated that the addition of GGBS and Fly Ash enhances the workability and compressive strength which eventually improved the mechanical properties of concrete.


Energies ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1135 ◽  
Author(s):  
Mateusz Sitarz ◽  
Izabela Hager ◽  
Marta Choińska

Geopolymers are considered to alternatives to Portland cement, providing an opportunity to exploit aluminosilicate wastes or co-products with promising performances in the construction sector. This research is aimed at investigating the strength of fly-ash-geopolymers of different ages. The effect of granulated blast furnace slag (GGBFS) as a partial replacement of fly ash (FA) on the tensile (ft) and compressive strength (fc), as well as the modulus of elasticity, is investigated. The main advantage of the developed geopolymer mixes containing GGBFS is their ability to set and harden at room temperature with no need for heating to obtain binding properties, reducing the energy consumption of their production processes. This procedure presents a huge advantage over binders requiring heat curing, constituting a significant energy savings and reduction of CO2 emissions. It is found that the development of strength strongly depends on the ratio of fly-ash to granulated blast furnace slag. With the highest amount of GGBFS, the compressive strength of geopolymers made of fly-ash reached 63 MPa after 28 days of curing at ambient temperature. The evolution of compressive strength with time is correlated with the development of ultrasound pulse velocity methods, which are used to evaluate maturity. The modulus of elasticity changes with strength and the relationship obtained for the geopolymer is presented on the basis of typical models used for cement-based materials. The tensile to compressive strength ratios of the tested geopolymers are identified as higher than for cementitious binders, and the ft(fc) relationship is juxtaposed with dependencies known for cement binders, showing that the square root function gives the best fit to the results.


Author(s):  
Khalid Bashir Mir

In this review study the usage of three different kinds of constructional materials was discussed in detail. The three materials comprised of Ground Granulated Blast Furnace Slag, fly and polypropylene fiber. Ground Granulated Blast Furnace Slag is basically the slag derived after the quenching process of iron slag produced during the processing of iron in iron industry. Fly ash is the waste generated from the coal processing industries and is mainly used in the road constructions works. Polypropylene fiber is a synthetic fiber that has very high tensile strength and flexural strength. This fiber is also known as synthetic fiber as it is mainly used in the synthetic industry. Depending upon the results of previous studies over the usage of these materials various conclusions has been drawn which are as follows. The results of studies related to the usage of Ground Granulated Blast Furnace Slag as partial replacement of cement concluded that the most optimum usage percentage of Ground Granulated Blast Furnace Slag as partial replacement of cement was found to be between 20 percent and 30 percent and beyond this limit the strength of concrete was decreasing. The past studies related to the usage of fly ash as partial replacement of cement shoed that the most optimum usage percentage of fly ash was found to be between 15 percent to 20 percent and beyond this percentage the strength parameters of concrete such as compressive strength, flexural strength and split tensile strength starts declining up to a greater extent. The studies related to the usage of polypropylene fiber showed that the usage of this fiber increases the compressive strength of soil and the most optimum results were found between 1.0 percent to 1.5 percent usages of polypropylene fiber. Above this percentage there will be negative effect on the strength aspects and the compressive strength starts declining.


2019 ◽  
Vol 9 (2) ◽  
pp. 183-186
Author(s):  
Abdul Razzaque Sandhu ◽  
Touqeer Ali Rind ◽  
Shahbaz Ali Kalhoro ◽  
Rahol Lohano ◽  
Faizan Hyder Laghari

Abstract Mortar is widely used in the construction industry for different purposes. Its compressive strength is the main parameter which is brought under focus. Compressive strength of mortars depends upon many factors such as water-cement ratio, fine aggregates size, and different curing conditions. This experimental study was undertaken to investigate the effect of GGBFS on compressive strength of mortars under different curing regimes using GGBFS as a partial replacement of cement. A total of 60 cubes of standard size of 2 x 2 x 2 inches were casted in laboratory, out of which 12 cubes each were prepared with 0%, 5%, 10%, 15% and 20% GGBFS replacement for cement. Cubes were cured for 3, 7, 14 and 28 days. Bases on obtained results it is observed that the maximum compressive strength was achieved by sample with 5% GGBFS, although 10% GGBFS samples achieved higher compressive strength than the control sample with 0% GGBFS. Further replacement beyond this value causes reduction in strength.


Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3448
Author(s):  
Chenhui Jiang ◽  
Aiying Wang ◽  
Xufan Bao ◽  
Zefeng Chen ◽  
Tongyuan Ni ◽  
...  

This paper presents an experimental investigation on geopolymer coatings (GPC) in terms of surface protection of civil structures. The GPC mixtures were prepared with a quadruple precursor simultaneously containing fly ash (FA), ground granulated blast-furnace slag (GBFS), metakaolin (MK), and Portland cement (OPC). Setting time, compressive along with adhesive strength and permeability, were tested and interpreted from a perspective of potential applications. The preferred GPC with favorable setting time (not shorter than 120 min) and desirable compressive strength (not lower than 35 MPa) was selected from 85 mixture formulations. The results indicate that balancing strength and setting behavior is viable with the aid of the multi-componential precursor and the mixture design based on total molar ratios of key oxides or chemical elements. Adhesive strength of the optimized GPC mixtures was ranged from 1.5 to 3.4 MPa. The induced charge passed based on a rapid test of coated concrete specimens with the preferred GPC was 30% lower than that of the uncoated ones. Setting time of GPC was positively correlated with η[Si/(Na+Al)]. An abrupt increase of setting time occurred when the molar ratio was greater than 1.1. Compressive strength of GPC was positively affected by mass contents of ground granulated blast furnace slag, metakaolin and ordinary Portland cement, and was negatively affected by mass content of fly ash, respectively. Sustained seawater immersion impaired the strength of GPC to a negligible extent. Overall, GPC potentially serves a double purpose of satisfying the usage requirements and achieving a cleaner future.


2015 ◽  
Vol 802 ◽  
pp. 142-148
Author(s):  
M.N. Noor Azline ◽  
Farah Nora Aznieta Abd Aziz ◽  
Arafa Suleiman Juma

The article reports a laboratory experimental programme that investigated effect of ground granulated blast furnace (GGBS) on compressive strength of POFA ternary concrete. Compressive strength tests were performed at a range of cements combinations, including 100%PC, two POFA levels for binary concrete, 35% and 45%, and 15%GGBS inclusion for POFA ternary concrete. The compressive strength results were examined in comparison to PC only and equivalent POFA binary concretes for up to 28 days. Results show that the reduction in compressive strength is greater with the higher cement replacement level for all concretes particularly for POFA binary concretes. However, 15%GGBS in POFA blended concrete has a comparable compressive strength compared to PC concrete at both, 35% and 45%, cement replacement levels except for ternary concrete at 0.65 w/c. In addition, the compressive strength of ternary concrete is slightly higher compared to binary concrete for all concrete combinations. Although there is no significant noticeable influence on strength development, the presence of GGBS did not adverse the strength development of POFA blended concrete. Thus, it can be concluded that GGBS compensates the adverse effect of POFA at early strength development.


2015 ◽  
Vol 802 ◽  
pp. 118-123 ◽  
Author(s):  
John Wilmer Bautista ◽  
John Benedict Crockett ◽  
Beatrice Ann Liu ◽  
Timothy John Obra ◽  
Cheryl Lyne Roxas

Drying shrinkage in mortar produces cracks and micro-cracks which affect the durability of a structure. The effects of seawater as a substitute to freshwater and fly ash as a partial replacement for cement were investigated in this study in order to address the predicted water shortage by 2025 and the increasing carbon footprint from carbon dioxide emissions worldwide. Moreover, these materials are also more economical alternatives to freshwater and cement. Rectangular prism specimens with varying fly ash content (10%, 15%, 20%, 25%, and 30%) were cast to measure the drying shrinkage in mortar while 50-mm cube mortar specimens were prepared to determine the compressive strength. This study investigated whether the addition of fly ash and seawater reduced the drying shrinkage of mortar. From the results, it was found that mortar specimens with 20% fly ash replacement achieved the highest early and late strengths. Partial substitution of fly ash would result to shrinkage in mortar while substitution of seawater to freshwater counteracts the effects of fly ash, thus producing less shrinkage. Fly ash content between 20%-25% combined with seawater produces the least shrinkage value without compromising the minimum required compressive strength.


2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Jun Yang ◽  
Qiang Wang ◽  
Yuqi Zhou

Plain cement concrete, ground granulated blast furnace slag (GGBS) concrete, and fly ash concrete were designed. Three wet curing periods were employed, which were 2, 5, and 8 days. The drying shrinkage values of the concretes were measured within 1 year after wet curing. The results show that the increasing rate of the drying shrinkage of concrete containing a mineral admixture at late age is higher than that of plain cement concrete regardless of the wet curing time. With the reduction of wet curing time, the increment of total drying shrinkage of concrete decreases with the decrease of the W/B ratio. The negative effects on the drying shrinkage of fly ash concrete due to the reduction of the wet curing time are much more obvious than those of GGBS concrete and plain cement concrete. Superfine ground granulated blast furnace slag (SGGBS) can reduce the drying shrinkage of GGBS concrete and fly ash concrete when the wet curing time is insufficient.


2021 ◽  
Vol 11 (2) ◽  
pp. 830
Author(s):  
Katarzyna Konieczna ◽  
Karol Chilmon ◽  
Wioletta Jackiewicz-Rek

The main assumption of eco-efficient High-Performance Concrete (HPC) design is the reduction of Portland cement clinker content without negatively affecting the composite’s mechanical and durability properties. In this paper, three low-clinker HPC mixtures incorporating slag cement (CEM III/B as per EN 197-1) and Supplementary Cementitious Materials (SCMs)—Ground Granulated Blast Furnace Slag (GGBFS), Siliceous Fly Ash (SFA) and Silica Fume (SF)—were designed. The maximum amount of Portland cement clinker from CEM III/B varied from 64 to 116 kg in 1 m3 of concrete mix. The compressive strength of HPC at 2, 7, 14, 28, 56, 90 days, and 2 years after casting, as well as the modulus of elasticity on 2-year-old specimens, was tested. The depth of water penetration under pressure and internal frost resistance in freeze–thaw tests were evaluated after 56 days of curing. Additionally, the concrete pH value tests were performed. The microstructure of 2-year-old HPC specimens was analyzed using Scanning Electron Microscopy (SEM). The research proved that it is possible to obtain low-clinker High-Performance Concretes that reach compressive strength of 76–92 MPa after 28 days of curing, show high values of modulus of elasticity (49–52 GPa) as well as increased resistance to frost and water penetration under pressure.


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