scholarly journals Analysis of Concrete Block by Partial Replacement of Cement with Fly Ash

2021 ◽  
pp. 15-19
Author(s):  
Vidya Sagar Khanduri ◽  
◽  
Shivek Sharma ◽  
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Setting Time ◽  
Control Level ◽  
Concrete Block ◽  
Target Strength ◽  
Partial Substitution ◽  
Partial Replacement ◽  
Sieve Analysis ◽  
Initial Strength

The objective of this research is to enhance the properties of concrete by using Fly Ash as a partial substitution of concrete. Tests carried out on cement are Initial and Final setting time and on aggregates, specific gravity and sieve analysis. The mean target strength with given compressive strength at 28 day and quality control level is calculated. Concrete blend proportions for the first tryout mix is calculated and casting of cube of 15mm size with curing for 28 days, and then test for strength using UTM/CTM machines. C-S-H gel as well as Calcium hydroxide as bi product when reacts with water. C-S-H gel has an ability to keep the ingredients together by making a proper bond whereas lime which is freely available can react with atmospheric moisture and cause efflorescence. In such cases if we use fly ash, it reacts with free lime and produces C-SH gel again and water as bi product. We have used Fly ash as a partial replacement of cement with variation of fly ash in percentage. In this study fly ash add in increment of 5%, 10%, 15%, 20%, 25%, 30% and 35% replacement of cement which has shown satisfactory results in the strength of the concrete. Fly Ash improved the workability of the concrete, decreases the bleeding, surface finish and increases the cohesiveness. Compressive strength is comparatively increased. The initial strength of concrete with fly ash has lower strength but acquires higher strength after 56 days; which shows that more the nos. of curing days more will be the strength. Thus, it can be used in areas of construction such as dams, pavements etc.

scholarly journals Analysis of Concrete Block by Partial Replacement of Cement with Fly Ash

2021 ◽  
Vol 1 (1) ◽  
pp. 15-19
Author(s):  
Vidya Sagar Khanduri ◽  
Shivek Sharma
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Setting Time ◽  
Control Level ◽  
Concrete Block ◽  
Target Strength ◽  
Partial Substitution ◽  
Partial Replacement ◽  
Sieve Analysis ◽  
Initial Strength

The objective of this research is to enhance the properties of concrete by using Fly Ash as a partial substitution of concrete. Tests carried out on cement are Initial and Final setting time and on aggregates, specific gravity and sieve analysis. The mean target strength with given compressive strength at 28 day and quality control level is calculated. Concrete blend proportions for the first tryout mix is calculated and casting of cube of 15mm size with curing for 28 days, and then test for strength using UTM/CTM machines. C-S-H gel as well as Calcium hydroxide as bi product when reacts with water. C-S-H gel has an ability to keep the ingredients together by making a proper bond whereas lime which is freely available can react with atmospheric moisture and cause efflorescence. In such cases if we use fly ash, it reacts with free lime and produces C-SH gel again and water as bi product. We have used Fly ash as a partial replacement of cement with variation of fly ash in percentage. In this study fly ash add in increment of 5%, 10%, 15%, 20%, 25%, 30% and 35% replacement of cement which has shown satisfactory results in the strength of the concrete. Fly Ash improved the workability of the concrete, decreases the bleeding, surface finish and increases the cohesiveness. Compressive strength is comparatively increased. The initial strength of concrete with fly ash has lower strength but acquires higher strength after 56 days; which shows that more the nos. of curing days more will be the strength. Thus, it can be used in areas of construction such as dams, pavements etc.

Drying Shrinkage of Fly Ash Mortar Mixed with Seawater

2015 ◽  
Vol 802 ◽  
pp. 118-123 ◽  
Author(s):  
John Wilmer Bautista ◽  
John Benedict Crockett ◽  
Beatrice Ann Liu ◽  
Timothy John Obra ◽  
Cheryl Lyne Roxas
Keyword(s):  
Carbon Dioxide ◽  
Compressive Strength ◽  
Fly Ash ◽  
Carbon Dioxide Emissions ◽  
Drying Shrinkage ◽  
Water Shortage ◽  
Ash Content ◽  
Partial Substitution ◽  
Partial Replacement ◽  
Micro Cracks

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.

scholarly journals Effect of Copolymer Latexes on Physicomechanical Properties of Mortar Containing High Volume Fly Ash as a Replacement Material of Cement

2014 ◽  
Vol 2014 ◽  
pp. 1-11
Author(s):  
El-Sayed Negim ◽  
Latipa Kozhamzharova ◽  
Yeligbayeva Gulzhakhan ◽  
Jamal Khatib ◽  
Lyazzat Bekbayeva ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Compressive Strength ◽  
Fly Ash ◽  
Setting Time ◽  
High Volume ◽  
Physicomechanical Properties ◽  
Partial Replacement ◽  
Setting Times ◽  
High Volume Fly Ash ◽  
Scanning Electron

This paper investigates the physicomechanical properties of mortar containing high volume of fly ash (FA) as partial replacement of cement in presence of copolymer latexes. Portland cement (PC) was partially replaced with 0, 10, 20, 30 50, and 60% FA. Copolymer latexes were used based on 2-hydroxyethyl acrylate (2-HEA) and 2-hydroxymethylacrylate (2-HEMA). Testing included workability, setting time, absorption, chemically combined water content, compressive strength, and scanning electron microscopy (SEM). The addition of FA to mortar as replacement of PC affected the physicomechanical properties of mortar. As the content of FA in the concrete increased, the setting times (initial and final) were elongated. The results obtained at 28 days of curing indicate that the maximum properties of mortar occur at around 30% FA. Beyond 30% FA the properties of mortar reduce and at 60% FA the properties of mortar are lower than those of the reference mortar without FA. However, the addition of polymer latexes into mortar containing FA improved most of the physicomechanical properties of mortar at all curing times. Compressive strength, combined water, and workability of mortar containing FA premixed with latexes are higher than those of mortar containing FA without latexes.

scholarly journals Effect of Ceramic Aggregate and Fly ash in Normal Strength Concrete

2019 ◽  
Vol 9 (1S3) ◽  
pp. 479-482
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Thermal Power ◽  
Strength Properties ◽  
Partial Replacement ◽  
Sieve Analysis ◽  
Normal Strength Concrete ◽  
Ceramic Insulator ◽  
Normal Strength

In this study, full and partial replacement of stone aggregate by ceramic insulator scrap and partial replacement of cement by fly ash has been done in order to enhance economy in construction. More once, the solution of disposal of wasting from ceramic insulator manufacturing company and thermal power plant is also achieved. Further various mechanical properties of ceramic insulator scrap such as crushing value, impact value, abrasion value, specific gravity, sieve analysis and water absorption has been studied and obtained to make the study fruitful. Concrete of grade M15 is used to study the compressive strength properties of stone and ceramic aggregates. Replacement of stone aggregates by ceramic aggregates has been done in stages starting from 0% to 100% each stage possessing the variation of 10% and in all the specimens 30% of cement is replaced by 35% of fly ash. Six number of cube samples are cast for each variation and the compressive strength of the same have been obtained at 7, 28 and 56 days of age. Totally 216 cubes are cast and tested for compression. It is found that the optimum percentage at which the stone aggregate can be replaced by ceramic aggregates is 50% and 30% of cement can be replaced by 35% fly ash.

scholarly journals Experimental Analysis on the Properties of Concrete Brick With Partial Replacement of Sand by Saw Dust and Partial Replacement of Coarse Aggregate by Expanded Polystyrene

2019 ◽  
Vol 5 ◽  
pp. 27-36
Author(s):  
Anjana Ghimire ◽  
Sanjeev Maharjan
Keyword(s):  
Compressive Strength ◽  
Water Absorption ◽  
Bulk Density ◽  
Coarse Aggregate ◽  
Setting Time ◽  
Maximum Size ◽  
Expanded Polystyrene ◽  
Partial Replacement ◽  
Sieve Analysis ◽  
Saw Dust

An experimental study had been conducted to study the effects of saw dust and EPS as partial replacement of sand and coarse aggregate in various percentages such as 0%, 10%, 20% and 30% in concrete brick samples of M20 and M15 Grade. Compressive strength, Bulk density and Water absorption of prepared saw dust and EPS M20 and M15 concrete brick were determined. The properties of materials were first determined before the conduction of experimental works. The normal consistency, initial and final setting time and compressive strength of cement used for the experiment were found as 31%,115 minutes, 265 minutes and 39.5 N/mm2 respectively. Sieve analysis to determine the particle size distribution of sand, coarse aggregates, saw dust and EPS was performed. From the sieve analysis, the nominal maximum size of sand, coarse aggregate, saw dust and EPS used for preparing concrete brick sample were 2.36 mm, 12.5 mm, 2.36 mm and 4.75 mm respectively. Impact value of coarse aggregate obtained was 11.20 %.The experimental results showed that water absorption of prepared M15 and M20 concrete brick samples increased with increase in percentage replacement of sand by saw dust and EPS by coarse aggregate. Compressive strength and Bulk density of prepared M15 and M20 concrete brick sample decreased with increase in percentage content of saw dust and EPS. The results showed that the partial replacement of sand by saw dust and coarse aggregate by EPS in concrete brick sample had sufficient strength as compared to common bricks.

scholarly journals Improvement of High-Volume Fly Ash Cementitious Material Using Single Alkali Activation

2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Wichian Chalee ◽  
Reaksmey Soeurt ◽  
Pumipat Pachana ◽  
Smith Songpiriyakij
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Setting Time ◽  
High Volume ◽  
Cementitious Material ◽  
Partial Replacement ◽  
Alkali Activation ◽  
Type I ◽  
Alkali Activator ◽  
High Volume Fly Ash

AbstractThis research aimed to present the improvement of the cementitious material in high-volume fly ash using only one alkali activator. Fly ash was used as a partial replacement for Portland cement type I, varying from 0 to 60% by weight of the binder. Concentrations of NaOH varying from 0.00 to 1.25 molar were used as alkali activator. Paste properties and mortar compressive strength at the ages of 3, 7, 14, 28, 60, and 90 days of water curing were investigated. The results reveal that fly ash paste with an alkali activator provides shorter initial setting time when compared to control paste without alkali activator. The use of 0.50 molar NaOH concentration in mortar containing fly ash not exceeding 50% by weight of binder provides the highest compressive strength at any age of curing. At that concentration, there is a significant increase in the 28-day compressive strength of up to 45% over that of the control mortar. In addition, higher NaOH concentration (not exceeding 1.00 molar) has a significant positive effect on the compressive strength of mortar with higher fly ash content, especially over longer curing periods.

scholarly journals EFFECT OF VOLCANIC ASH AS PARTIAL REPLACEMENT OF CEMENT IN CONCRETE SUBJECT TO AGGRESSIVE CHEMICAL ENVIRONEMNT

2021 ◽  
Vol 6 (5) ◽  
Author(s):  
Agboola Shamsudeen Abdulazeez ◽  
Amina Omolola Suleiman ◽  
Simdima Gabriel Gideon ◽  
Solomon Wutong Poki
Keyword(s):  
Compressive Strength ◽  
Volcanic Ash ◽  
Setting Time ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Target Strength ◽  
Partial Replacement ◽  
Hardened Concrete ◽  
Split Tensile Strength ◽  
Concrete Production

- Presently researches all over the world is concentrating on alternative materials as partial cement replacement in concrete production. The use of pozzolanic material in concrete is becoming increasingly important because of the need for more sustainable cementing products. Volcanic ash is a form of natural pozzolan and has a chemical composition comparable to other supplementary cementitious materials. In this paper, volcanic ash was used to partially replace cement in the ratio of 0%, 5%, 10%, 15% and 20% by volume in concrete and cured in H2SO4 and MgSO4 environment. 28-day target strength was adopted and concrete tested at 7, 14, 28 and 56 days’ hydration period. Specific gravity, bulk density and setting time test on volcanic ash were carried out. Fresh concrete tests such as slump and compacting factor test were carried out along-side hardened concrete tests like compressive strength and split tensile strength. The result shows that the maximum compressive strength at 28 days was at 0% control concrete, while at 56 days the maximum strength was observed at 10% replacement of cement with volcanic ash and it is considered as optimum percentage replacement.

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
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Construction Industry ◽  
Optimal Level ◽  
Partial Substitution ◽  
Partial Replacement ◽  
Curing Time ◽  
Granulated Blast Furnace Slag ◽  
Strength Tests ◽  
Furnace Slag

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.

scholarly journals A Review of How the Characteristics of Concrete is Altered when Fly Ash is used as a Partial Replacement for Cement

2021 ◽  
Vol 5 (2) ◽  
pp. 72-80
Author(s):  
Heba Adnan
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Fly Ash ◽  
High Performance ◽  
Building Materials ◽  
Low Cost ◽  
Setting Time ◽  
Construction Materials ◽  
Partial Replacement ◽  
Cement Manufacturing

Cement is one of the most widely used building materials on the planet. Cement manufacturing has also increased carbon emissions to their greatest level in recent years. Alternative or low-emissions binders have become more popular as a partial cement substitute in recent years. Because of its huge yearly output as waste material and low cost, fly ash is now regarded as one of the most accessible choices. Fly ash-based construction materials have a lot of promise as cement substitutes because of their high performance and inexpensive cost. The purpose of this article is to look at how fly ash affects the workability, setting time, compressive strength, and tensile strength of concrete. The kinds and characteristics of fly ash were also investigated.

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