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 ◽  
...  

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.

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3322
Author(s):  
Mugineysh Murali ◽  
Bashar S. Mohammed ◽  
Isyaka Abdulkadir ◽  
M. S. Liew ◽  
Wesam Salah Alaloul

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.


As construction in India and other developing countries are increasing, the consumption of energy and resources are also increasing in same alarming way. Due to urbanization many industries are developed and the industrial wastage is also increasing day by day which is a serious concern to the environment. Many industries produce various end products, which may be used in construction industry at various places. So we focused on some of the waste materials which can be replaced in conventional concrete, and by then cost of construction can be reduced and is economical, also damage caused to the environment can also be reduced, at the same time landfills can also be reduced. So, we focused on reducing the virgin materials in concrete like cement, fine aggregate and coarse aggregate by replacing them with some waste materials which have same properties of cement, fine aggregate and coarse aggregate. The objective of the present work is to find out the effectiveness of fly ash, quarry dust and crumb rubber by replacing them in varied percentages. Here, cement is replaced by fly ash with percentages as 30%, 40%, 50%, 60% and quarry dust as fine aggregate with percentages of 20%, 30%, 40%, 50% along with crumb rubber as coarse aggregate with percentages as 5%, 10%, 15%, 20%. The results in this study have shown a gradual reduction of compressive strength as we kept on adding the crumbed rubber. Even though the strength obtained for 5% usage of crumbed rubber was quite satisfactory.


Author(s):  
Naraindas Bheel ◽  
Paul O. Awoyera ◽  
Oladimeji B. Olalusi

In recent years, recycled materials mostly available in abundant quantities in local agricultural fields are considered as potential constituent material for concrete production. Also, cement production emits many toxic gases in the atmosphere, which causes environmental pollution and greenhouse gases. Thus, recyc;ed materials, such as fly ash (FA), wheat straw ash (WSA), and maize corn ash (MCA) are condered as cementitious binders in concrete for sustainable development. This study aims to determine the engineering properties of concrete with a ternary blend of fly ash, wheat straw ash, and maize cob ash. A total of 73 concrete cubes, 42 reinforced concrete prisms and 42 concrete cylinders were cast to examine mechanical properties of concrete at 7, 28, and 56 curing days. At 28 days (maturity period), the experimental results showed an increase in compressive, tensile, and flexural strength by 12.28%, 9.33%, and 9.93%, respectively, at 9% substitution of ternary cementitious materials (TCM). However, the density of concrete was reduced by 9.92%, with an increase in the TCM content after 28 days. Moreover, the modulus of elasticity was improved by 14.23% with an increase in the content of TCM up to 18% after 28 days, and drying shrinkage of concrete was reduced with the introduction of TCM content after 50 days. However, the workability of fresh concrete decreased as the percentage of TCM increased. Results of this study proved that agricultural materials investgated could be good fit as binder in cementitious composites.


Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 488
Author(s):  
Sylvia Kelechi ◽  
Musa Adamu ◽  
Abubakar Mohammed ◽  
Yasser Ibrahim ◽  
Ifeyinwa Obianyo

Waste tire disposal continues to pose a threat to the environment due to its non-biodegradable nature. Therefore, some means of managing waste tires include grinding them to crumb rubber (CR) sizes and using them as a partial replacement to fine aggregate in concrete. However, the use of CR has a series of advantages, but its major disadvantage is strength reduction. This leads to the utilization of calcium carbide waste (CCW) to mitigate the negative effect of CR in self-compacting concrete (SCC). This study investigates the durability properties of SCC containing CR modified using fly ash and CCW. The durability properties considered are water absorption, acid attack, salt resistance, and elevated temperature of the mixes. The experiment was conducted for mixes with no-fly ash content and their replica mixes containing fly ash to replace 40% of the cement. In the mixes, CR was used to partially replace fine aggregate in proportions of 0%, 10%, and 20% by volume, and CCW was used as a partial replacement to cement at 0%, 5%, and 10% by volume. The results indicate that the mixes containing fly ash had higher resistance to acid (H2SO4) and salt (MgSO4), with up to 23% resistance observed when compared to the mix containing no fly ash. In addition, resistance to acid attack decreased with the increase in the replacement of fine aggregate with CR. The same principle applied to the salt attack scenario, although the rate was more rapid with the acid than the salt. The results obtained from heating indicate that the weight loss was reduced slightly with the increase in CCW, and was increased with the increase in CR and temperature. Similarly, the compressive strength was observed to slightly increase at room temperature (27 °C) and the greatest loss in compressive strength was observed between the temperature of 300 and 400 °C. However, highest water absorption, of 2.83%, was observed in the mix containing 20% CR, and 0% CCW, while the lowest water absorption, of 1.68%, was found in the mix with 0% CR, 40% fly ash, and 10% CCW. In conclusion, fly ash is recommended for concrete structures immersed in water, acid, or salt in sulphate- and magnesium-prone areas; conversely, fly ash and CR reduce the resistance of SCC to heat beyond 200 °C.


Author(s):  
Stephen Isaac

The overall production of the cement has greatly increased which results lots of problems in environment as it involves the emission of CO2   gas.  Environmental concerns, stemming from the high energy expense and carbon dioxide emission associated with cement manufacture have brought about pressures to reduce cement consumption through the use of supplementary materials. Materials such as Metakaolin, fly ash have good pozzolanic activity and are a good material for the production of high strength concrete. Copper slag is a by-product of copper extraction by smelting. Copper slag can be used in concrete production as a partial replacement for sand. However, it is expected that the use of Metakaolin, Fly ash and Copper slag in concrete improves the strength properties of concrete. Keywords: Supplementary cementitious material, Cement, Fine aggregate


Author(s):  
Olusola Emmanuel Babalola ◽  
Paul O. Awoyera

Supplementary cementitious materials are most needed to enhance a sustainable development in poor communities. It is pertinent to investigate the suitability of such alternative materials for construction. The present study evaluates the strength characteristics of concrete made with varied proportion of Cordia millenii ash blended with Portland cement. Chemical composition of Cordia millenii and the setting time when blended with cement was determined. Other laboratory tests performed on Cordia millenii blended cement include: sieve analysis and specific gravity. Five replacement percentages of Cordia millenii (5%, 10%, 15%, and 20%) were blended with cement in concrete. Control specimens were also produced with only cement. Tests to determine the workability, air entrained, bulk density and compressive strength properties of the concrete were also conducted. Results obtained revealed that optimum Cordia millenii mix is 10%, which yielded the highest density and compressive strength in the concrete.


2013 ◽  
Vol 815 ◽  
pp. 227-232
Author(s):  
Jie Dai ◽  
Jian Min Xiong ◽  
Jin Zhi Zhou

The experiment program was carried out to investigate strength performance and flexural properties of concrete containing recycled crumb rubber. The rubber contents of 10,20,30 and 40% by volume were selected to partially replace the fine aggregate with crumb rubber of 20 mesh, and sodium hydroxide (NaOH) solution was employed to modify the rubber surface, enhancing adhesion between rubber particles and cement paste. Uniaxial compression and four point bending tests showed that both compressive and flexural strength reduced as crumb rubber inclusion increasing. It is notable that surface modification by NaOH solution have positive effects on strength properties of crumb rubber concrete, and the failure mode tends to become ductile failure due to the rubber inclusion rather than brittle failure of normal concrete.


Author(s):  
Aikot Pallikkara Shashikala ◽  
Praveen Nagarajan ◽  
Saranya Parathi

Production of Portland cement causes global warming due to the emission of greenhouse gases to the environment. The need for reducing the amount of cement is necessary from sustainability point of view. Alkali activated and geopolymeric binders are used as alternative to cement. Industrial by-products such as fly ash, ground granulated blast furnace slag (GGBS), silica fume, rice husk ash etc. are commonly used for the production of geopolymer concrete. This paper focuses on the development of geopolymer concrete from slag (100% GGBS). Effect of different cementitious materials such as lime, fly ash, metakaolin, rice husk ash, silica fume and dolomite on strength properties of slag (GGBS) based geopolymer concrete are also discussed. It is observed that the addition of dolomite (by-products from rock crushing plants) into slag based geopolymer concrete reduces the setting time, enhances durability and improves rapidly the early age strength of geopolymer concrete. Development of geopolymer concrete with industrial by-products is a solution to the disposal of the industrial wastes. The quick setting concrete thus produced can reduce the cost of construction making it sustainable also.


2017 ◽  
Vol 886 ◽  
pp. 159-163 ◽  
Author(s):  
Suppachai Sinthaworn

Slump of fresh concrete, compressive strength and water penetration depth under pressure of fly ash concrete incorporate with quarry waste as fine aggregate were investigated. The cementitious materials of the concrete includes ordinary Portland cement 80% and fly ash 20% by weight of cementitious. The mix proportions of the concrete were set into two classes of compressive strength. The results show that fly ash enhances workability of both concretes (normal concrete and concrete incorporate with quarry waste). Increasing the percentage of quarry dusts as fine aggregate in concrete seem negligible effect on the compressive strength whereas adding fly ash shows a slightly improve the compressive strength in the case of cohesive concrete mixture. Besides, adding the suitable amount of fly ash could improve the permeability of concrete. Therefore, fly ash could be a good admixture to improve the water resistant of normal strength concrete and also could be a supplemental material to improve the compressive strength of normal high strength concrete.


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