scholarly journals Properties of Concrete Prepared with Recycled Aggregates Treated by Bio-Deposition Adding Oxygen Release Compound

Materials ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2147 ◽  
Author(s):  
Yaguang Zhu ◽  
Quanquan Li ◽  
Peizhen Xu ◽  
Xiangrui Wang ◽  
Shicong Kou
Keyword(s):  
Compressive Strength ◽  
Water Absorption ◽  
High Water ◽  
Treatment Method ◽  
Recycled Aggregates ◽  
Culture Solution ◽  
Oxygen Release ◽  
Micro Cracks ◽  
Concrete Production ◽  
New Treatment

Recycled aggregates have high water absorption and crushing index. In order to improve the properties of recycled aggregates in concrete production, various treatments were used to modify the aggregates. In recent years, bio-deposition as a new treatment method of recycled aggregates was environmentally friendly. An improved method of bio-deposition was implemented to modify the properties of recycled mortar aggregates (RMA). O-bio-deposition is based on aerobic bacteria induced CaCO3 precipitation by respiration by varying the distance between the RMA and the bottom of the container and by adding an oxygen release compound to the culture solution that contains bacteria to promote the induction of CaCO3. First, the physical properties, including water absorption, crushing value, and apparent density, of the coarse RMA under different treatment methods were determined, and an o-bio-deposition treatment method was obtained. The fine RMA was treated and compared with the untreated RMA. Concretes were then prepared from the treated coarse RMA, and compressive strength and slump were determined. In addition, the effect of the o-bio-deposition treatment on the RMA surface and the micro-cracks of concretes were observed by scanning electron microscopy (SEM). It was found that the water absorption and crushing index of the coarse RMA treated by o-bio-deposition were reduced by 40.38 and 19.76% compared with untreated RMA, respectively. Regarding the concrete, the slump and the compressive strength (28 d) of concrete were increased by 115% and 25.3%, respectively compared with the untreated concrete.

scholarly journals The Influence of Discharge Time, Kind of Additive, and Kind of Aggregate on the Properties of Three-Stage Mixed Concrete

2018 ◽  
Vol 10 (11) ◽  
pp. 3862 ◽  
Author(s):  
Alena Sicakova ◽  
Karol Urban
Keyword(s):  
Compressive Strength ◽  
Water Absorption ◽  
Recycled Concrete ◽  
Recycled Aggregates ◽  
Concrete Aggregate ◽  
Discharge Time ◽  
Concrete Mixtures ◽  
Concrete Properties ◽  
Concrete Production ◽  
The Impact

Application of recycled aggregates (RA) for concrete production is limited due to their poor quality. While the environmental benefits of using the RA are well accepted, some unsolved problems prevent this type of material from wide application in structural concrete. The research and development of techniques which can minimize the adverse effect of RA on the concrete properties are highly requested. A specific mixing approach can also be helpful; here, mineral additives play a significant role for improvement of RA performance within the mixing process. However, delivery process can influence the homogeneity and uniformity of the concrete mixtures, resulting in negative effect on technical parameters. In this study, the impact of delivery time (0 min, 45 min, and 90 min) on the set of hardened concrete properties is presented while the three-stage mixing is used. Two kinds of additives—fly ash (FA) and recycled concrete powder (RCP)—were tested to coat the coarse fraction of recycled concrete aggregate (RCA) in the first step of mixing. For comparison, cement as coating material and natural aggregate instead the RCA were also used. The following parameters were tested after 28 days of setting and hardening: density, compressive strength, splitting tensile strength, water absorption capacity, and depth of penetration of water under pressure. Generally, 90 min of working with concrete mixtures left no significantly negative influence on tested characteristics. Based on ANOVA results, with prolonged discharge time, the changes in composition of the mixtures become less important for compressive strength, density, and water absorption.

EFFECT OF RECYCLED CONCRETE AGGREGATE QUALITY ON PROPERTIES OF CONCRETE

2020 ◽  
Vol 15 (2) ◽  
pp. 57-69
Author(s):  
Daniel Hatungimana ◽  
Şemsi Yazıcı ◽  
Ali Mardani-Aghabaglou
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Water Absorption ◽  
Recycled Concrete ◽  
Recycled Aggregates ◽  
Concrete Aggregate ◽  
Hardened Concrete ◽  
Recycled Concrete Aggregate ◽  
Waste Concrete ◽  
Concrete Production

ABSTRACT The possibility of the use of recycled aggregates from the construction industry in green concrete production is of increasing importance to reduce the negative environmental impact associated with construction and demolition wastes. The objective of this study is to investigate the effect of recycled concrete aggregate (RCA) quality on the properties of hardened concrete properties such as compressive strength, splitting tensile strength, density, water absorption capacity and porosity accessible to water. The RCA used in this study was obtained from the crushing of waste concrete with two different compressive strengths (LRCA obtained from the crushing of waste concrete having compressive strengths below 30 MPa and HRCA obtained from the crushing of waste concrete having compressive strengths above 30 MPa). The natural coarse limestone aggregate was 100% replaced with coarse LRCA and HRCA. As a result of the study, the use of 100% HRCA and %100 LRCA instead of limestone coarse aggregate in the concrete adversely affected its mechanical and physical properties. In addition, HRCA showed better performance in terms of compressive strength, tensile strength, water absorption and porosity compared to the use of LRCA. Furthermore, the percentage of adhered mortar on the surface of LRCA and HRCA was analyzed using a computerized micro tomography device, and it was found that the percentages of attached mortar and aggregates are 61% and 35.5% for LRCA, whilst the attached mortar and aggregate contents for HRCA are 45.9% and 53.7%, respectively.

scholarly journals OPTIMUM PERFORMANCE OF STABILIZED EDE LATERITE AS AN ALTERNATIVE CONSTRUCTION MATERIAL

2020 ◽  
Vol 3 (8) ◽  
pp. 1-8
Author(s):  
Adegbenle Bukunmi O
Keyword(s):  
Compressive Strength ◽  
Water Absorption ◽  
Construction Material ◽  
High Water ◽  
Good Alternative ◽  
Linear Shrinkage ◽  
Absorption Capacity ◽  
Water Absorption Capacity ◽  
Optimum Performance ◽  
High Water Absorption

Laterite samples from Ede area with particle components of 19.7% clay, 32.8% silt and 47.5% sand was stabilized with combined cement, lime and bitumen and test for Compressive strength, Linear Shrinkage, Permeability and Water Absorption. The stabilizers were mixed with laterite soil in different ratios and percentage. The laterite carried 90% which is constant while the three stabilizers shared the remaining 10% in varying form. After 28 days of curing, laterite stabilizer with 90% of laterite, 8% of cement, 1% lime and 1% bitumen (LCLB1) possessed compressive strength of 2.01N/mm2. It Water Absorption Capacity was 3.05%. LCLB4 stabilizer (90% laterite, 6% cement, 2% lime and 2% bitumen) has the same compressive strength with LCLB1 stabilizer but with a high Water Absorption Capacity of 4.2%. The stabilizer of 90% laterite, 3.33% cement, 3.33% lime and 3.33% of bitumen (LCLB8) has the lowest compressive strength of 0.74N/mm2 and the highest Water Absorption Capacity of 5.39%. The results shows that LCLB1 stabilizer is a better stabilizer for strength and blocks made from laterite stabilized with it stand a good alternative to sand Crete blocks in building constructions. The combination of these stabilizers in order to determine a most economical volume combination for optimum performance is highly possible and economical.

scholarly journals Comparative Strength and Cost of Rice Husk Concrete Block

2019 ◽  
Vol 280 ◽  
pp. 04002
Author(s):  
Setya Winarno
Keyword(s):  
Compressive Strength ◽  
Water Absorption ◽  
Rice Husk ◽  
Concrete Block ◽  
Strength Analysis ◽  
Normal Concrete ◽  
Comparative Cost ◽  
Concrete Production ◽  
Sustainable Materials ◽  
The Cost

This research presents a comparative cost and strength analysis of rice husk concrete block which is aimed at reducing the cost of concrete production and emphasizing environmentally and friendly sustainable materials. Concrete block materials consist of cement, filler, and rice husk. Tests were performed to compare the strength and cost of seven cement rice husk weight ratios designated ranging from 0.67 to 2.00 with constant water cement ration of 0.4. Samples have been tested for 28-day strength. The analysis of the results has showed that the higher proportions of rice husk correspond to decreased strength dan cost polynomially. At 134% proportion of rice husk, it is optimum value for rice husk concrete block. In this point, the compressive strength satisfies the standard. Also, water absorption of 16,04% justifies the maximum standard. Overall, the cost of 134% RH concrete is Rp 511,809 per m3 which is 42.5% cheaper than normal concrete block.

The Recycled Aggregates with Surface Treatment by Pozzolanics

2005 ◽  
Vol 287 ◽  
pp. 63-68 ◽  
Author(s):  
Jae Jun Kim ◽  
Sang Heum Youn ◽  
M.J. Cho ◽  
H.T. Shin ◽  
Jeong Bae Yoon ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Surface Treatment ◽  
Water Absorption ◽  
Recycled Aggregates ◽  
Scanning Electron Micrographs ◽  
Cement Mortars ◽  
Pozzolanic Materials ◽  
Adsorption Treatment ◽  
Scanning Electron

To improve the mechanical properties of concretes containing recycled aggregates, pozzolanic materials were used to decrease the porosity of the recycled aggregates. These pozzolanic materials were adhered on the surface of recycled aggregates and closed the open pores so that the water absorption was decreased 1~2% as the amount of adsorption was increased. Compressive strength of cement mortars and concretes using surface treated recycled aggregates reaches above 95% of the strength of its natural counterparts. Investigation of the microstructures using the scanning electron micrographs showed the formation of dense interface after the adsorption treatment of pozzolanics to recycled aggregates.

Measuring the water absorption of recycled aggregates, what is the best practice for concrete production?

2016 ◽  
Vol 123 ◽  
pp. 690-703 ◽  
Author(s):  
M. Quattrone ◽  
B. Cazacliu ◽  
S.C. Angulo ◽  
E. Hamard ◽  
A. Cothenet
Keyword(s):  
Water Absorption ◽  
Best Practice ◽  
Recycled Aggregates ◽  
Concrete Production

scholarly journals Reusing of Construction Debris in Plain Concrete Elements

2021 ◽  
Vol 9 (3) ◽  
pp. 81-87
Author(s):  
A. Abdelrahman Abuserriya ◽  
B. Bashir H. Osman ◽  
C. Salma Y. Mahmoud
Keyword(s):  
Compressive Strength ◽  
Sea Water ◽  
Plain Concrete ◽  
Absorption Capacity ◽  
Recycled Concrete ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Aggregate Content ◽  
Concrete Production ◽  
Concrete Blocks

Construction is a serious environmental problem and a challenge for people who concerned with sustainability in the construction field. Previous studies showed positive results for the use of recycled aggregates in the concrete production. This study portrays the results for utilizing construction debris for casting different types of concrete blocks. The recycled concrete debris was used in different ratios (0%, 50%, and 100%) in replacement for natural coarse aggregates for different targeted compressive strength (B250, B300, B350 and B400). Two types of water (pure and sea water) were used for curing the blocks. In addition, hollow block and paving block were casted with different ratios of recycled aggregate (0%, 20%, 45% and 100%) and cured with two types of water. The results showed a decrease in compressive strength with the increase recycled aggregate content. It was also noticed that the absorption capacity increases with high recycled aggregate content.  

scholarly journals Evaluation of Cassava Effluent as Organic Admixture in Concrete Production for Farm Structures

2020 ◽  
pp. 271-282
Author(s):  
Ovie Isaac AKPOKODJE ◽  
Goodnews Goodman AGBI ◽  
Hilary UGURU
Keyword(s):  
Compressive Strength ◽  
Water Absorption ◽  
Fresh Water ◽  
Absorption Rate ◽  
International Standards ◽  
Partial Replacement ◽  
Strength Development ◽  
Water Absorption Rate ◽  
Concrete Production ◽  
Farm Structures

This paper evaluated the influence of cassava effluent on the compressive strength of concrete for farm structures. Three sets of concrete cubes were produced with a concrete mix ratio of 1:2:4 (C 15) and a water to cement ratio (w c-1) of 0.5. The 1st set was produced with 100% fresh water (tap water). The 2nd set was produced with 75% partial replacement of the fresh water with fresh cassava effluent, while the 3rd set was produced with 75% partial replacement of the fresh water with old cassava effluent. The density, water absorption rate and compressive strength of the concrete cubes was tested in accordance with ASTM International standards, at the end of 7, 14, 21, 28 and 56 curing days. The results revealed that, the cassava effluent slightly increased the cubes density; but reduced their water absorption rate. The study further showed that, concrete produced with fresh cassava effluent, developed the highest compressive strength (29.57 MPa) at the end of the 56th curing day. In contrast, concrete produced with old cassava effluent developed the lowest compressive strength (24.43 MPa) at day 56, which was lower than the compressive strength of 27.18 MPa developed by the concrete produced with fresh water (also at day 56). In addition, the cassava effluent retarded the initial rate of strength development, as such, increasing its prospect as an organic concrete admixture. This study will be helpful in mitigating the harmful effects of cassava effluent in the environment, since it can be utilized in concrete production.

scholarly journals Experimental Investigation of Concrete with Recycled Aggregates for Suitability in Concrete Structures

2019 ◽  
Vol 9 (23) ◽  
pp. 5010
Author(s):  
Arkadiusz Denisiewicz ◽  
Małgorzata Śliwa ◽  
Krzysztof Kula ◽  
Tomasz Socha
Keyword(s):  
Experimental Investigation ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Water Absorption ◽  
Frost Resistance ◽  
Experimental Tests ◽  
Strength Properties ◽  
Recycled Aggregates ◽  
Total Shrinkage ◽  
Structural Applications

This paper presents the experimental tests of concrete made on the recycled aggregates basis. Tests were carried out to determine the concrete suitability for construction purposes. The physical and strength properties were determined for three types of recycling aggregates. The aggregates were obtained from sanitary ceramics ‘SC’ (washbasins and toilet bowls), building ceramics ‘BC’ (solid bricks), and concrete rubble ‘CR’. The results obtained in tests of compressive strength, bending tensile strength, water absorption, total shrinkage, watertightness, and frost resistance of concrete made of SC and CR aggregates gave grounds for stating its suitability for structural purposes. Concrete based on the BC aggregates is not recommended for structural applications.

scholarly journals Influence of Parent Concrete Properties on Compressive Strength and Chloride Diffusion Coefficient of Concrete with Strengthened Recycled Aggregates

Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4631 ◽  
Author(s):  
Jingwei Ying ◽  
Zewen Han ◽  
Luming Shen ◽  
Wengui Li
Keyword(s):  
Compressive Strength ◽  
Diffusion Coefficient ◽  
Water Absorption ◽  
Recycled Aggregates ◽  
Chloride Diffusion ◽  
Chloride Diffusion Coefficient ◽  
Wide Range ◽  
Different Types ◽  
Compressive Strength Of Concrete ◽  
Silica Slurry

Parent concrete coming from a wide range of sources can result in considerable differences in the properties of recycled coarse aggregate (RCA). In this study, the RCAs were obtained by crushing the parent concrete with water-to-cement ratios (W/Cparent) of 0.4, 0.5 and 0.6, respectively, and were strengthened by carbonation and nano-silica slurry wrapping methods. It was found that when W/Cparen was 0.3, 0.4 and 0.5, respectively, compared with the mortar in the untreated RCA, the capillary porosity of the mortar in the carbonated RCA decreased by 19%, 16% and 30%, respectively; the compressive strength of concrete containing the carbonated RCA increased by 13%, 11% and 13%, respectively; the chloride diffusion coefficient of RAC (DRAC) containing the nano-SiO2 slurry-treated RCA decreased by 17%, 16% and 11%; and that of RAC containing the carbonated RCA decreased by 21%, 25% and 26%, respectively. Regardless of being strengthened or not, both DRAC and porosity of old mortar in RCAs increased with increasing W/Cparent. For different types of RCAs, DRAC increased obviously with increasing water absorption of RCA. Finally, a theoretical model of DRAC considering the water absorption of RCA was established and verified by experiments, which can be used to predict the DRAC under the influence of different factors, especially the water absorption of RCA.

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