scholarly journals Producing Green Concrete with Plastic Waste and Nano Silica Sand

2021 ◽  
Vol 11 (6) ◽  
pp. 7932-7937
Author(s):  
M. F. Qasim ◽  
Z. K. Abbas ◽  
S. K. Abed

Industrial and urban development has resulted in the spread of plastic waste and the increase in the emissions of carbon dioxide resulting from the cement manufacturing process. The current research aims to produce green (environmentally friendly) concrete by using plastic waste as coarse aggregates in different proportions (10% and 20%) and nano silica sand powder as an alternative to cement in different proportions (5% and 10% by weight). The results showed that compressive strength decreased by 12.10% and 19.23% for 10% and 20% plastic waste replacement and increased by 12.89% and 20.39% for 5% and 10% silica sand replacement respectively at 28 days. Flexural strength decreased by 12.95% and 19.64% for 10% and 20% plastic waste replacement and increased by 11.16% and 19.86% for 5% and 10% silica sand replacement. Splitting tensile strength decreased by 12.74% and 20.22% for 10% and 20% plastic waste replacement and increased by 10.86% and 19.66% for 5% and 10% silica sand replacement. Dry density decreased by 4.51% and 7.83% for 10% and 20% plastic waste replacement and increased by 2.78% and 4.10% for 5% and 10% silica sand replacement respectively at 28 days.

2018 ◽  
Vol 162 ◽  
pp. 02029
Author(s):  
Wasan Khalil ◽  
Nazar Al Obeidy

This investigation includes the use of 15% of glass wastes as a partial substitution to cement in combination with plastic wastes as volumetric replacement to natural coarse aggregate to produce sustainable concrete. Different volumetric replacements of plastic waste to natural coarse aggregate (25%, 50%, 75%, and 100%) were used in concrete containing 15% glass powder as a replacement by weight of cement. Generally, the results show that the inclusion of 15% glass powder improves the compressive strength, splitting tensile strength and flexural strength by about 13.3%, 36.3%, and 34.7%respectively at 60 day age in comparison with reference concrete without wastes, also the results show a decrease in water absorption and an increase in dry density. The inclusion of plastic waste aggregate in the presence of 15% glass powder leads to a decrease in the compressive strength, flexural strength, splitting tensile strength, dry density, ultrasonic pulse velocity, and thermal conductivity. The percentage reductions are 59.8%, 46.3%, 43.6%, 20.5%, 28.6%, and 54.4% respectively for concrete specimens that including 100% plastic waste coarse aggregate in comparison with concrete specimens without plastic waste aggregate.


2021 ◽  
Vol 15 (1) ◽  
pp. 22-28
Author(s):  
Erniati Bachtiar ◽  
◽  
Muh Arief Muzakkir ◽  
Takwin Takwin ◽  
Sri Gusty ◽  
...  

Plastic represent thousands of materials with different physical, mechanical, and chemical properties. As plastic demand and usage increase, it is undeniable that the amount of plastic waste will increase. Plastic has the features of which cannot rot; it does not decompose naturally; it cannot absorb water or cannot rust. So it will eventually cause problems for the environment. This study aims to determine the compressive strength and tensile strength of concrete mixes that use coarse aggregates of plastic waste as a substitute for natural aggregates / broken rocks. There are three variations of samples made with mutations in the type of plastic used, namely PP (Polypropylene) plastic, PET (Polyethylene Terephthalate) plastic, and PP & PET combination plastic. The specimen is cylindrical, with a size of 10 cm x 20 cm. Compressive strength and tensile strength testing is carried out at 28 days according to SNI standards. The results obtained the compressive strength obtained on each variation of standard concrete samples, PP aggregate concrete, PET aggregate concrete, and PP & PET aggregate concrete, respectively, of 21.64 MPa, 10.61 MPa, 8.48 MPa, and 10.18 MPa. Whereas for the splitting tensile strength of standard concrete, PP aggregate concrete, PET aggregate concrete, and PP & PET aggregate concrete respectively were 2.86 MPa, 1.80 MPa, 1.70 MPa, and 1.80 MPa.


Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 556
Author(s):  
Muhammad Faisal Javed ◽  
Afaq Ahmad Durrani ◽  
Sardar Kashif Ur Rehman ◽  
Fahid Aslam ◽  
Hisham Alabduljabbar ◽  
...  

Numerous research studies have been conducted to improve the weak properties of recycled aggregate as a construction material over the last few decades. In two-stage concrete (TSC), coarse aggregates are placed in formwork, and then grout is injected with high pressure to fill up the voids between the coarse aggregates. In this experimental research, TSC was made with 100% recycled coarse aggregate (RCA). Ten percent and twenty percent bagasse ash was used as a fractional substitution of cement along with the RCA. Conventional concrete with 100% natural coarse aggregate (NCA) and 100% RCA was made to determine compressive strength only. Compressive strength reduction in the TSC was 14.36% when 100% RCA was used. Tensile strength in the TSC decreased when 100% RCA was used. The increase in compressive strength was 8.47% when 20% bagasse ash was used compared to the TSC mix that had 100% RCA. The compressive strength of the TSC at 250 °C was also determined to find the reduction in strength at high temperature. Moreover, the compressive and tensile strength of the TSC that had RCA was improved by the addition of bagasse ash.


2009 ◽  
Vol 2009 ◽  
pp. 1-9 ◽  
Author(s):  
Aly Ahmed ◽  
Medhat Shehata ◽  
Said Easa

An experimental work was conducted to study the use of factory-waste roof shingles to enhance the properties of fine-grained soil used in road works. Cement kiln dust (CKD), a cogenerated product of Portland cement manufacturing, was used as a stabilizing agent while the processed shingles were added to enhance the soil tensile strength. The effects of shingles on strength and stability were evaluated using the unconfined compressive strength, splitting tensile strength, and California Bearing Ratio (CBR) tests. The results showed that the use of CKD alone resulted in a considerable increase in the unconfined compressive strength but had a small effect on the tensile strength. The addition of shingles substantially improved the tensile strength of the stabilized soil. A significant reduction in the capillary rise and a slight decrease in the permeability were obtained as a result of shingle addition. An optimal shingle content of 10% is recommended to stabilize the soil.


2008 ◽  
Vol 3 (4) ◽  
pp. 130-137 ◽  
Author(s):  
R Kumutha ◽  
K Vijai

The properties of concrete containing coarse recycled aggregates were investigated. Laboratory trials were conducted to investigate the possibility of using recycled aggregates from the demolition wastes available locally as the replacement of natural coarse aggregates in concrete. A series of tests were carried out to determine the density, compressive strength, split tensile strength, flexural strength and modulus of elasticity of concrete with and without recycled aggregates. The water cement ratio was kept constant for all the mixes. The coarse aggregate in concrete was replaced with 0%, 20%, 40%, 60%, 80% and 100% recycled coarse aggregates. The test results indicated that the replacement of natural coarse aggregates by recycled aggregates up to 40% had little effect on the compressive strength, but higher levels of replacement reduced the compressive strength. A replacement level of 100% causes a reduction of 28% in compressive strength, 36% in split tensile strength and 50% in flexural strength. For strength characteristics, the results showed a gradual decrease in compressive strength, split tensile strength, flexural strength and modulus of elasticity as the percentage of recycled aggregate used in the specimens increased. 100% replacement of natural coarse aggregate by recycled aggregate resulted in 43% savings in the cost of coarse aggregates and 9% savings in the cost of concrete.


2020 ◽  
Vol 10 (3) ◽  
pp. 5728-5731 ◽  
Author(s):  
S. A. Chandio ◽  
B. A. Memon ◽  
M. Oad ◽  
F. A. Chandio ◽  
M. U. Memon

This research paper aims at investigating the effects of fly ash as cement replacement in green concrete made with partial replacement of conventional coarse aggregates with coarse aggregates from demolishing waste. Green concrete developed with waste materials is an active area of research as it helps in reducing the waste management issues and protecting the environment. Six concrete mixes were prepared using 1:2:4 ratio and demolishing waste was used in equal proportion with conventional aggregates, whereas fly ash was used from 0%-10% with an increment of 2.5%. The water-cement ratio used was equal to 0.5. Out of these mixes, one mix was prepared with all conventional aggregates and was used as the control, and one mix with 0% fly ash had only conventional and recycled aggregates. The slump test of all mixes was determined. A total of 18 cylinders of standard size were prepared and cured for 28 days. After curing the compressive strength of the specimens was evaluated under gradually increasing load until failure. It is observed that 5% replacement of cement with fly ash and 50% recycled aggregates gives better results. With this level of dosage of two waste materials, the reduction in compressive strength is about 11%.


2021 ◽  
Author(s):  
Palash Badjatya ◽  
Abdullah Akca ◽  
Daniela Fraga Alvarez ◽  
Baoqi Chang ◽  
Siwei Ma ◽  
...  

This study describes and demonstrates a carbon-negative process for manufacturing cement from widely abundant seawater-derived magnesium (Mg) feedstocks. In contrast to conventional Portland cement, which starts with carbon-containing limestone as the source material, the proposed process uses membrane-free electrolyzers to facilitate the conversion of carbon-free magnesium ions (Mg2+) in seawater into magnesium hydroxide (Mg(OH)2) precursors for the production of Mg-based cement. After a low-temperature carbonation curing step converts Mg(OH)2 into magnesium carbonates through reaction with carbon dioxide (CO2), the resulting Mg-based binders can exhibit compressive strength comparable to that achieved by Portland cement after curing for only two days. Although the proposed “cement-from-seawater” process requires similar energy use per ton of cement as existing processes, its potential to achieve a carbon-negative footprint makes it highly attractive to decarbonize one of the most carbon intensive industries.


Author(s):  
Shahid Bashir

Abstract: Cement production is one of the sources that emit carbon dioxide, in addition to deforestation and combustion of fossil fuels also leads to ill effects on environment. The global cement industry accounts for 7% of earth’s greenhouse gas emission. To enhance the environmental effects associated with cement manufacturing and to constantly deplore natural resources, we need to develop other binders to make the concrete industry sustainable. This work offers the option to use waste paper sludge ash as a partial replacement of cement for new concrete. In this study cement in partially replaced as 5%, 10%, 15% and 20% by waste paper sludge ash in concrete for M25 mix and tested for compressive strength, tensile strength, water absorption and dry density up to the age of 28days and compared it with conventional concrete, based on the results obtained, it is found that waste paper ash may be used as a cement replacement up to 5% by weight and the particle size is less the 90µm to prevent reduction in workability. Keywords: slump test, Compressive strength, split tensile strength, water absorption test, Waste Paper Sludge Ash Concrete, Workability.


2019 ◽  
Vol 3 (2) ◽  
pp. 81-89
Author(s):  
Angga Pirman Firdaus ◽  
Jonbi

Indonesia ranks second in the world's largest plastic waste producer after China. Each year, Indonesia can contributeup to 187.2 million tons of plastic waste, while China reaches 262.9 million tons of plastic waste. Based on the data, one way to utilize plastic waste by using plastic waste as a mixture of concrete, where the plastic used is polypropylene (PP) plastic with different percentage of concrete mixture, the test includes compressive strength test and tensile concrete. The results of concrete compressive strength testing with polypropylene (PP) plastic waste mixture of 5%, 10% and 15% at age 28 in aggregate aggregate mixture decreased by 5.15%, 6.89% and 13.53%. As for the result of concrete tensile strength test with polypropylene (PP) plastic waste mixture of 5%, 10% and 15% at age 28 in crude aggregate mixture decreased 17,61%, 24,13% dan 23,24%.


Author(s):  
Moein Khoshroo ◽  
Ali Akbar Shirzadi Javid ◽  
Nima Rajabi Bakhshandeh ◽  
Mohamad Shalchiyan

In this study, the effect of using crumb rubber and recycled aggregates on the mechanical properties of concrete has been evaluated as areplacement of fine and coarse aggregates In order to add the admixtures and evaluate their combined effect, 20 different types of concrete mixture ratio were prepared. The results indicated that in those samples containing crumb rubber and recycled aggregates the compressive strength is reduced and adding fiber up to 0.1%. to these concrete samples can improve the compressive strength Also, the tensile strength of the samples mixed with crumb rubber and recycled aggregates were decreased, and with the addition of propylene fiber up to 0.4%. the tensile strength slightly increased Moreover by adding the crumb rubber to the samples the elasticity modulus was reduced but by adding fiber to samples about 0.1% and 0.2.% the modulus of elasticity of concrete in all samples were increased. According to the results, it can be said that using the combination of 5% of crumb rubber as a replacement of fine aggregate, and the combination of 35% of recycled aggregates as a replacement of coarse aggregate, and also by adding 0.1% polypropylene fiber in volumetric percentage of concrete along with adding 7% of micro silica as a replacement of cement led to the best effect on the mechanical properties of concrete.


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