scholarly journals Material Characterization for Sustainable Concrete Paving Blocks

2019 ◽  
Vol 9 (6) ◽  
pp. 1197 ◽  
Author(s):  
Xinyi Wang ◽  
Chee Chin ◽  
Jun Xia
Keyword(s):  
Water Absorption ◽  
Crumb Rubber ◽  
Recycled Concrete ◽  
Recycled Aggregates ◽  
Waste Materials ◽  
Fine Aggregate ◽  
Significant Deterioration ◽  
Sustainable Concrete ◽  
Coarse Aggregates ◽  
Slip Resistance

Recycled aggregates have been widely studied and used in concrete products nowadays. There are still many waste materials that can be used as recycled aggregates other than crushed concrete particles. This paper aims to study the property variations of sustainable concrete paving block incorporating different contents of construction wastes. Five different types of waste materials were used in this project, including: recycled concrete coarse aggregate (RCCA), recycled concrete fine aggregate (RCFA), crushed glass (CG), crumb rubber (CB), and ground granulated blast furnace slag (GGBS). According to the test results of the properties of blocks mixed with different levels of wastes materials, it is concluded that adding both RCCA and RCFA in the block can decrease its strength and increase the water absorption. The suggested replacement levels for RCCA and RCFA are 60% and 20%, respectively. Mixing crushed glass in the concrete paving blocks as a type of coarse aggregates can improve the blocks’ strength and decrease the blocks’ water absorption. Addition of crumb rubber causes a significant deterioration of blocks’ properties except for its slip resistance.

scholarly journals Strength and Water Absorption of Sustainable Concrete Produced with Recycled Basaltic Concrete Aggregates and Powder

2021 ◽  
Vol 13 (11) ◽  
pp. 6277
Author(s):  
Ibrahim Sharaky ◽  
Usama Issa ◽  
Mamdooh Alwetaishi ◽  
Ahmed Abdelhafiz ◽  
Amal Shamseldin ◽  
...  
Keyword(s):  
Water Absorption ◽  
Edge Length ◽  
Recycled Concrete ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Partial Substitution ◽  
Small Reduction ◽  
Concrete Aggregates ◽  
Recycled Concrete Aggregates ◽  
Sustainable Concrete

In this study, the recycled concrete aggregates and powder (RCA and RCP) prepared from basaltic concrete waste were used to replace the natural aggregate (NA) and cement, respectively. The NA (coarse and fine) was replaced by the recycled aggregates with five percentages (0%, 20%, 40%, 60% and 80%). Consequently, the cement was replaced by the RCP with four percentages (0%, 5%, 10% and 20%). Cubes with 100 mm edge length were prepared for all tests. The compressive and tensile strengths (fcu and ftu) and water absorption (WA) were investigated for all mixes at different ages. Partial substitution of NA with recycled aggregate reduced the compressive strength with different percentages depending on the type and source of recycled aggregate. After 28 days, the maximum reduction in fcu value was 9.8% and 9.4% for mixtures with coarse RCA and fine RCA (FRCA), respectively. After 56 days, the mixes with 40% FRCA reached almost the same fcu value as the control mix (M0, 99.5%). Consequently, the compressive strengths of the mixes with 10% RCA at 28 and 56 days were 99.3 and 95.2%, respectively, compared to those of M0. The mixes integrated FRCA and RCP showed higher tensile strengths than the M0 at 56 d with a very small reduction at 28 d (max = 3.4%). Moreover, the fcu and ftu values increased for the late test ages, while the WA decreased.

Investigation of the mechanical properties of concrete containing recycled aggregate and scrap crumb rubber and polypropylene fibers

2020 ◽  
pp. 147776062097750
Author(s):  
Moein Khoshroo ◽  
Ali Akbar Shirzadi Javid ◽  
Nima Rajabi Bakhshandeh ◽  
Mohamad Shalchiyan
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Polypropylene Fiber ◽  
Crumb Rubber ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Fine Aggregate ◽  
Mixture Ratio ◽  
Coarse Aggregates

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.

scholarly journals Partial Replacement of Fine Aggregate Using Waste Materials in Concrete as Roof Tile: A Review

2021 ◽  
Vol 1200 (1) ◽  
pp. 012008
Author(s):  
K Supar ◽  
F A A Rani ◽  
N L Mazlan ◽  
M K Musa
Keyword(s):  
Water Absorption ◽  
Crumb Rubber ◽  
Waste Material ◽  
Waste Materials ◽  
Partial Replacement ◽  
Fine Aggregate ◽  
Coconut Fiber ◽  
Roof Tile ◽  
Fine Aggregates ◽  
Stone Dust

Abstract The use of waste material as a partial replacement has become popular in concrete mixture studies. Many research has utilized waste materials like cement, fine aggregate, coarse aggregate, and reinforcing materials substitute. The current paper focuses on some of the waste elements that are utilized in a concrete mortar (use in roof tile) as a partial replacement for fine aggregates such as rubber ash, sawdust, seashells, crumb rubber, pistachio shells, cinder sand, stone dust, and copper slag. There are many variations of mix proportion and water-cement ratio for every waste material. Compressive strength was compared and found that stone dust and the combination of seashell and coconut fiber shows an incensement when used to replacing fine aggregate. The suitable replacement level for stone dust is 25% and 50%. While the suitable replacement levels for the combination of sea shell and coconut fiber are 20% and 30%. Material from the rubber families such as rubber crumb and rubber ash is only suitable for replacement levels. Rubber families especially rubber crumbs have shown low water absorption value which is good in the production of roofing products. As we know, the roof should have waterproof properties to prevent any leaks from happening when it rains. Most of the waste materials added as fine aggregates in concrete have increased the amount of water absorption and found that sawdust is the most abundant material with a high percentage of water absorption compared to the others. Research on the partial replacement of fine aggregates replaced with waste materials is needed more extensively to provide more confidence about their use in concrete mortars, especially on roof tiles.

Durability Performance of Polymeric Waste Crumb Rubber as Fine Aggregates Replacement in Concrete

2015 ◽  
Vol 1129 ◽  
pp. 508-515
Author(s):  
D.S.Q. Abg Adenan ◽  
Kartini Kamaruddin
Keyword(s):  
Water Absorption ◽  
Water Permeability ◽  
Crumb Rubber ◽  
Waste Materials ◽  
Fine Aggregate ◽  
Rubberized Concrete ◽  
Fine Aggregates ◽  
Polymeric Waste ◽  
Durability Performance ◽  
Waste Crumb Rubber

This paper presents a study on durability performance of polymeric waste crumb rubber as partial fine aggregates replacement in concrete grade 30. The use of aggregates as constituent in concrete production commonly lead to a question about the sources of natural aggregates since concrete consumption has been increasing nowadays. Rubberized concrete has been introduced whereby natural fine aggregates are being replaced with crumb rubber in concrete since there are problems with availability of natural sand as fine aggregate material. Besides, polymeric waste materials production has been increasing. Crumb rubber used in this study was manufactured by special mill where scrap tire rubber is grinded and screened into smaller size of particles. Rubberized concrete is produced by mixing with different percentages of 10, 20 and 30% of crumb rubber as fine aggregates replacement. Water cement ratio of 0.53 and curing periods for 28 days and 60 days were considered in this study. The water absorption test was conducted to determine the percentages of water absorption, while water permeability test was conducted to determine the coefficient of permeability in concrete. Absorption and permeability are governed by the capillary pores in the cement paste. Pores that are too large resulted in high absorption and permeability, while pores that are small resulted in a low absorption and permeability. The durability performance in term of water absorption and water permeability in concrete was improved by introducing crumb rubber as polymeric waste materials to replace fine aggregates in concrete. The recycling and reusing of polymeric waste materials in concrete attract the interest worldwide which can promote sustainability and reduce the high environmental impact of the concrete technology.

scholarly journals Caracterización físico-mecánica del hormigón estructural fabricado con áridos reciclados: comparativa experimental con sustitución de áridos finos y gruesos = Physical-mechanical characterization of the structural concrete made with recycled aggregates: experimental comparative with substitution of fine and coarse aggregates

2017 ◽  
Vol 3 (1) ◽  
pp. 24
Author(s):  
Sara Valverde Fernández
Keyword(s):  
Water Absorption ◽  
Modulus Of Elasticity ◽  
Shrinkage Strain ◽  
Construction And Demolition Waste ◽  
Recycled Aggregates ◽  
Fine Aggregate ◽  
Demolition Waste ◽  
Coarse Aggregates ◽  
Static Modulus ◽  
Static Modulus Of Elasticity

ResumenEste trabajo estudia las propiedades mecánicas y físicas de hormigones estructurales fabricados con áridos reciclados obtenidos de residuos de construcción y demolición. Se han seleccionado mezclas con una relación específica agua / cemento y una sustitución de agregados gruesos y finos similares. Se han comparado los resultados de la deformación, la resistencia a la compresión, la resistencia a la rotura por fraccionamiento, el módulo estático de elasticidad, la deformación por contracción, la densidad aparente y los ensayos de absorción de agua. Los datos muestran que las propiedades más afectadas debido a la sustitución de agregados naturales por agregados reciclados son la trabajabilidad, el módulo de elasticidad, la deformación por contracción y la absorción de agua.AbstractThis work studies the mechanical and physical properties of structural concretes made by recycled aggregates obtained from construction and demolition waste. Mixes with a specific water/cement ratio and a similar coarse and fine aggregate substitution have been selected. Results from slump, compressive strength, splitting tensile strength, static modulus of elasticity, shrinkage strain, bulk density and water absorption tests have been compared. The data show that the most affected properties because of natural aggregate substitution for recycled aggregates are workability, modulus of elasticity, shrinkage strain and water absorption.

scholarly journals Effect of Fly Ash on the Compressive Strength of Green Concrete

2020 ◽  
Vol 10 (3) ◽  
pp. 5728-5731 ◽  
Author(s):  
S. A. Chandio ◽  
B. A. Memon ◽  
M. Oad ◽  
F. A. Chandio ◽  
M. U. Memon
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Recycled Aggregates ◽  
Waste Materials ◽  
Partial Replacement ◽  
Equal Proportion ◽  
Standard Size ◽  
Green Concrete ◽  
Coarse Aggregates ◽  
Management Issues

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%.

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.

scholarly journals Investigation of the Use of Recycled Concrete Aggregates Originating from a Single Ready-Mix Concrete Plant

2018 ◽  
Vol 8 (11) ◽  
pp. 2149 ◽  
Author(s):  
Eleftherios Anastasiou ◽  
Michail Papachristoforou ◽  
Dimitrios Anesiadis ◽  
Konstantinos Zafeiridis ◽  
Eirini-Chrysanthi Tsardaka
Keyword(s):  
Soil Stabilization ◽  
Coarse Fraction ◽  
Recycled Concrete ◽  
Recycled Aggregates ◽  
Hardened Concrete ◽  
Fine Aggregate ◽  
Waste Products ◽  
Concrete Aggregates ◽  
Recycled Concrete Aggregates ◽  
Concrete Mixtures

The waste produced from ready-mixed concrete (RMC) industries poses an environmental challenge regarding recycling. Three different waste products form RMC plants were investigated for use as recycled aggregates in construction applications. Crushed hardened concrete from test specimens of at least 40 MPa compressive strength (HR) and crushed hardened concrete from returned concrete (CR) were tested for their suitability as concrete aggregates and then used as fine and coarse aggregate in new concrete mixtures. In addition, cement sludge fines (CSF) originating from the washing of concrete trucks were tested for their properties as filler for construction applications. Then, CSF was used at 10% and 20% replacement rates as a cement replacement for mortar production and as an additive for soil stabilization. The results show that, although there is some reduction in the properties of the resulting concrete, both HR and CR can be considered good-quality recycled aggregates, especially when the coarse fraction is used. Furthermore, HR performs considerably better than CR both as coarse and as fine aggregate. CSF seems to be a fine material with good properties as a filler, provided that it is properly crushed and sieved through a 75 μm sieve.

Influence of the Crushing Process of Recycled Aggregates on Concrete Properties

2014 ◽  
Vol 634 ◽  
pp. 151-162 ◽  
Author(s):  
Diogo Pedro ◽  
Jorge de Brito ◽  
Luís Evangelista
Keyword(s):  
Water Absorption ◽  
Recycled Concrete ◽  
Recycled Aggregates ◽  
Efficient Production ◽  
Capillary Water ◽  
Concrete Aggregates ◽  
Recycled Concrete Aggregates ◽  
Carbonation Resistance ◽  
Chloride Penetration Resistance ◽  
Durability Performance

This work intends to evaluate the (mechanical and durability) performance of concrete made with coarse recycled concrete aggregates (CRCA) obtained using two crushing processes: primary crushing (PC) and primary plus secondary crushing (PSC). This analysis intends to select the most efficient production process of recycled aggregates (RA). The RA used here resulted from precast products (P), with strength classes of 20 MPa, 45 MPa and 65 MPa, and from laboratory-made concrete (L) with the same compressive strengths. The evaluation of concrete was made with the following tests: compressive strength; splitting tensile strength; modulus of elasticity; carbonation resistance; chloride penetration resistance; capillary water absorption; and water absorption by immersion. These findings contribute to a solid and innovative basis that allows the precasting industry to use without restrictions the waste it generates.

scholarly journals Microstructural analysis of concretes manufactured with recycled coarse aggregates pre-soaked using different methods

2020 ◽  
Vol 70 (339) ◽  
pp. 228 ◽  
Author(s):  
Z. Sánchez-Roldán ◽  
I. Valverde-Palacios ◽  
I. Valverde-Espinosa ◽  
M. Martín-Morales
Keyword(s):  
Microstructural Analysis ◽  
Treatment Method ◽  
Absorption Capacity ◽  
Recycled Concrete ◽  
Recycled Aggregates ◽  
Negative Effects ◽  
Optimal Method ◽  
Transition Zones ◽  
Coarse Aggregates

Recycled concrete has a microstructure more complex than natural concrete, as it includes new interfacial transition zones, the quality of which is conditioned by the state of humidity of the aggregates used, which in turn will affect the final properties of the concrete. Bearing in mind the greater absorption capacity of recycled aggregates, it is important to improve its properties by means of a treatment method that is capable of reducing the negative effects that this may produce in the new concrete. Therefore, the influence of the pre-soaking method of recycled aggregates on the formation of the microstructure of concretes manufactured with these aggregates is analysed, to determine which treatment is the most effective for the production of concretes for non-structural use. The results show that the microstructure of the evaluated concretes differs according to the treatment method used, the most optimal method being one that uses aggregates without pre-soaking.

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