scholarly journals Utilization of Crumb Rubber and High-Volume Fly Ash in Concrete for Environmental Sustainability: RSM-Based Modeling and Optimization

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3322
Author(s):  
Mugineysh Murali ◽  
Bashar S. Mohammed ◽  
Isyaka Abdulkadir ◽  
M. S. Liew ◽  
Wesam Salah Alaloul
Keyword(s):  
Fly Ash ◽  
Environmental Sustainability ◽  
High Volume ◽  
Crumb Rubber ◽  
Cementitious Materials ◽  
Partial Replacement ◽  
Fine Aggregate ◽  
High Volume Fly Ash ◽  
Concrete Production ◽  
Rubber Concrete

Waste tire and fly ash (FA) are two waste materials whose disposal and rapid rate of accumulation are among the pressing sources of concern and threat to the environment. Although much research exists on the use of these materials in cementitious composites, very little literature is available on the effectiveness of combining them in high volumes for concrete production. This work aimed to utilize crumb rubber (CR) from waste tires as a partial replacement of fine aggregate at 15%, 22.25%, and 30% by volume, and high-volume fly ash (HVFA) replacement of cement at 50%, 60%, and 70% (by weight of cementitious materials) to produce high-volume fly ash–crumb rubber concrete (HVFA–CRC). Using the central composite design (CCD) option of the response surface methodology (RSM), 13 mixes were produced with different combinations and levels of the CR and FA (the input factors) on which the responses of interest (compressive, flexural, and tensile strengths) were experimentally investigated. Furthermore, the composite influence of CR and HVFA on the workability of the concrete was assessed using the slump test. The results showed a decline in the mechanical properties with increasing replacement levels of the CR and HVFA. However, up to 22.25% and 60% of CR and HVFA replacements, respectively, produced a structural HVFA–CRC with a compressive strength of more than 20 MPa at 28 days. Response predictive models were developed and validated using ANOVA at a 95% confidence level. The models had high R2 values ranging from 95.26 to 97.74%. Multi-objective optimization was performed and validated with less than 5% error between the predicted and experimental responses.

Chemical attack on concrete containing a high volume of crumb rubber as a partial replacement to fine aggregate in engineered cementitious composite (ECC)

2021 ◽  
Author(s):  
Wesam Salah Alaloul ◽  
Muhammad Ali Musarat ◽  
Sani Haruna ◽  
Bassam Tayeh ◽  
Muhammad Nurzahin Bin Norizan
Keyword(s):  
Compressive Strength ◽  
High Volume ◽  
Crumb Rubber ◽  
Cementitious Materials ◽  
Partial Replacement ◽  
Fine Aggregate ◽  
Cementitious Composite ◽  
Conventional Concrete ◽  
Engineered Cementitious Composite ◽  
Chemical Attack

This research has been conducted where the focus is on the chemical attack towards the Engineered Cementitious Composite (ECC) containing a high volume of the crumb rubber in terms of durability, behaviour, and comparison with conventional concrete. Two variables have been considered in developing rubberized ECC mixtures, i.e. the amount of crumb rubber as a replacement to fine aggregate by volume of 0-30% and PVA fibres by volume of 0-2% to cementitious materials. The resistance properties of ECC incorporating crumb rubber were investigated for 13 different variable combinations developed by Response Surface Methodology (RSM). The experimental results revealed that the presence of crumb rubber in the ECC matrix enhanced the resistance of the ECC in both acidic and sulphate environments. It was also revealed that by incorporating 15% of crumb rubber, the loss of compressive strength significantly reduced from 38% to 15%

scholarly journals Equivalent CO2 Emission and Cost Analysis of Green Self-Compacting Rubberized Concrete

2021 ◽  
Vol 14 (1) ◽  
pp. 137
Author(s):  
Sylvia E. Kelechi ◽  
Musa Adamu ◽  
Abubakar Mohammed ◽  
Ifeyinwa I. Obianyo ◽  
Yasser E. Ibrahim ◽  
...  
Keyword(s):  
Fly Ash ◽  
Co2 Emission ◽  
Calcium Carbide ◽  
Crumb Rubber ◽  
Cementitious Materials ◽  
Strength Properties ◽  
Cementitious Material ◽  
Ternary Blend ◽  
Fine Aggregate ◽  
Concrete Production

Global warming and climate changes are the major environmental challenges globally. With CO2 emission being one of the main greenhouse gases emitted to the environment, and cement and concrete production amounting to about 10% of the global CO2 emission, there is a need for the construction industry to utilize an environmentally sustainable material as an alternative to cement. This study analyzed the cost, CO2 emission and strength properties of green self-compacting concrete (SCC) ternary blend containing fly ash, calcium carbide residue (CCR), and crumb rubber (CR) as a replacement material by volume of cement, cementitious material, and fine aggregate, respectively. Cement was replaced with fly ash at 0 and 40% by volume. CCR was used as a replacement at 5 and 10% by volume of cementitious materials, CR replaced fine aggregate in proportions of 10 and 20% by volume. The result indicated that the mix with 0% fly ash and 20% CR replacement of fine aggregate was the most expensive and had the highest CO2 emission. However, the mix with 10% CR, 40% fly ash, and 10% CCR had the lowest CO2 emission and was therefore the greenest SCC mix. The 28-day maximum compressive strength of 45 MPa was achieved in a mix with 0% CR, 0% fly ash, and 10% CCR, while the utmost 28-day splitting tensile strength of 4.1 MPa was achieved with a mix with 10% CR, 0% fly ash, and 5% CCR, and the highest flexural strength at 28 days was 6.7 MPa and was also obtained in a mix with 0% CR, 0% fly ash, and 5% CCR. In conclusion, a green SCC can be produced by substituting 40% cement with fly ash, 10% fine aggregate with CR, and 10% CCR as a replacement by volume of cementitious material, which is highly affordable and has an acceptable strength as recommended for conventional SCC.

scholarly journals Electrochemical Characteristics of High-Volume Fly Ash Lightweight Aggregate Concrete Incorporating Hydrated Lime

2020 ◽  
Vol 38 (11A) ◽  
pp. 1629-1639
Author(s):  
Tareq S. Al-Attar ◽  
Basil S. Alshathr ◽  
Mahmood E. Mohammed
Keyword(s):  
Fly Ash ◽  
Lightweight Concrete ◽  
High Volume ◽  
Hydrated Lime ◽  
Cementitious Materials ◽  
Chloride Ions ◽  
Partial Replacement ◽  
Lightweight Aggregate Concrete ◽  
Electrochemical Characteristics ◽  
High Volume Fly Ash

Currently, the use of  high-volume fly ash lightweight concrete, HVFALWC, has acquired popularity as a durable, resource-efficient, and an option of sustainability for varying concrete applications. Electrochemical characteristics such as half- cell potential, AC resistance, chloride penetration, free chloride, and pH value, up to 180 days were investigated for this type of concrete that uses 50% and 60% of fly ash as a replacement of Portland cement. The effect of using 10% hydrated lime powder as a partial substitute for the weight of cementitious materials for HVFALWC on electrochemical properties was also studied. The results in this study showed the possibility of producing friendly environmental structural lightweight concrete by using high volume fly ash (50% and 60%) as partial replacement by weight of cement. Furthermore, using 10% hydrated lime as partial replacement by weight of cementitious materials could be considered as a reliable measure to reduce the effect of chloride ions in the corrosion process.

scholarly journals Effects of the Loss on Ignition of Fly Ash on the Properties of High-Volume Fly Ash Concrete

2019 ◽  
Vol 11 (9) ◽  
pp. 2704 ◽  
Author(s):  
How-Ji Chen ◽  
Neng-Hao Shih ◽  
Chung-Hao Wu ◽  
Shu-Ken Lin
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Modulus Of Elasticity ◽  
High Volume ◽  
Cementitious Materials ◽  
Hardened Concrete ◽  
Fine Aggregate ◽  
Loss On Ignition ◽  
High Volume Fly Ash ◽  
Hardened Properties

This study presents the experimental results of fresh and hardened properties of concrete incorporating high-volume fly ash (HVFA). Two kinds of low-calcium fly ash with loss on ignition (LOI) of 5% and 8% were used as replacement for cement and/or fine aggregate of 0% (control), 20%, 40%, 50%, 60% and 80% by weight of the total cementitious materials. The properties of fresh concrete tested included the slump, air content, unit weight and setting time; those of hardened concrete determined included compressive strength, modulus of elasticity, flexural strength and drying shrinkage. Test results indicate that the concretes made with high-LOI (8%) fly ash can be successfully produced for structural concrete, which contains fly ash of up to 60% of the total cementitious materials. The high-LOI fly ash-concretes with higher replacement levels presented longer setting times. However, although both the fresh and hardened properties of high LOI fly ash concretes were inferior to those of the low-LOI (5%) fly ash concretes, the high modulus of elasticity, the adequate strength development characteristics both at early and later ages (up to 365 days) and the low dry shrinkage were observed when compared to those of the control concrete with a comparable 28-day compressive strength of 30 MPa.

scholarly journals Development of High Volume Fly Ash Concrete Incorporating Steel Fibre

2020 ◽  
Vol 9 (2) ◽  
pp. 426-433
Keyword(s):  
Fly Ash ◽  
Aspect Ratio ◽  
Thermal Power ◽  
High Volume ◽  
Fine Aggregate ◽  
Fly Ash Concrete ◽  
High Volume Fly Ash ◽  
Hardened Properties ◽  
Very High ◽  
Split Tensile Test

Concrete is most frequently used composite material. Concrete is homogeneous mix of fine aggregate, Coarse aggregate and binding medium of concrete paste .Due to `high demand of cement Co2 emission is very high, It leads to global warming. So in this project high volume fly ash concrete was incorporated. Fly ash is the waste material obtained from thermal power plant. In this paper we investigated about high volume fly ash in different percentage of replacement 55, 60, 75 percentage. Layered pavement is incorporated with Steel fiber in a different aspect ratio (15, 30, 40).layered pavement will give good thermal expansive properties. By varying fly ash content and Steel fibers Aspect ratio of different mixes were arrived hardened properties of these nine mixes were arrived such as Compression test, Split tensile test and Flexural test.

scholarly journals Mechanical Properties of High-Volume Fly Ash Strain Hardening Cementitious Composite (HVFA-SHCC) for Structural Application

Materials ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 2607 ◽  
Author(s):  
Chenhua Jin ◽  
Chang Wu ◽  
Chengcheng Feng ◽  
Qingfang Zhang ◽  
Ziheng Shangguan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Strain Hardening ◽  
Construction Material ◽  
High Volume ◽  
Partial Replacement ◽  
Cementitious Composite ◽  
Multiple Cracking ◽  
High Volume Fly Ash ◽  
Structural Applications

Strain-hardening cementitious composite (SHCC) is a kind of construction material that exhibits multiple cracking and strain-hardening behaviors. The partial replacement of cement with fly ash is beneficial to the formation of the tensile strain-hardening property of SHCC, the increase of environmental greenness, and the decrease of hydration heat, as well as the material cost. This study aimed to develop a sustainable construction material using a high dosage of fly ash (no less than 70% of the binder material by weight). Based on the micromechanics analysis and particle size distribution (PSD) optimization, six mixes with different fly ash to cement ratios (2.4–4.4) were designed. The mechanical properties of the developed high-volume fly ash SHCCs (HVFA-SHCCs) were investigated through tensile tests, compressive tests, and flexural tests. Test results showed that all specimens exhibited multiple cracking and strain-hardening behaviors under tension or bending, and the compressive strength of the designed mixes exceeded 30MPa at 28 days, which is suitable for structural applications. Fly ash proved to be beneficial in the improvement of tensile and flexural ductility, but an extremely high volume of fly ash can provide only limited improvement. The HVFA-SHCC mix FA3.2 (with fly ash to binder ratio of about 76% by weight) designed in this study is suggested for structural applications.

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.

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