scholarly journals Study on Strength Characteristics by using Fully Recycled Coarse Aggregate Concrete at Various Atmospheric Conditions

2020 ◽  
pp. 80-85
Author(s):  
P Ganga Prasad S Naveen Kumar and
Keyword(s):  
Coarse Aggregate ◽  
Sea Water ◽  
Research Work ◽  
Strength Characteristics ◽  
Recycled Aggregates ◽  
Acid Attack ◽  
Demolition Waste ◽  
Recycled Coarse Aggregate ◽  
Coarse Aggregates ◽  
Shrinkage And Creep

A large amount of construction waste has been dramatically increased in the last decade and environmental concerns on the recycling of waste has been increased. Mostly nowadays developing countries are demolishing some million tons of concrete wastages from the old buildings. So they are using Recycled aggregates for future construction. In this paper recycled coarse aggregate used 100%. In our research work, we have collected the demolition waste from our village cement concrete road was demolished for the purpose of renovation. The demolished road is of M20 grade concrete and age of concrete is 8years. Nowadays construction of any concrete structure requires huge amount of natural coarse aggregate. So they are using demolition waste, to reduce the cost of purchasing natural coarse aggregate. Recycled coarse aggregate are separated from the demolished waste by using equipment's. To improve the quality of recycled coarse aggregate by using treatment method's. The recycled coarse aggregates are weak in drying of shrinkage and creep. To control the drying of shrinkage and creep by using fly ash etc .The strength characteristics of natural coarse aggregate and recycled coarse aggregates. Recycled coarse aggregate are successful utilization in many countries such as European, American and Russia. This paper present's the investigation of strength characterstics due to effect of various temperature changes such as sulphate attack, acid attack , sea water and normal water.

scholarly journals Mechanical Properties of Geopolymer Concrete Made With Partial Replacement of Coarse Aggregate by Recycled Aggregate

2019 ◽  
Vol 9 (1) ◽  
pp. 2301-2304 ◽  
Keyword(s):  
Mechanical Properties ◽  
Sodium Hydroxide ◽  
Sodium Silicate ◽  
Coarse Aggregate ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Partial Replacement ◽  
Geopolymer Concrete ◽  
Recycled Coarse Aggregate ◽  
Coarse Aggregates

Construction is the one the fast growing field in the worldwide. There are many environmental issues connected with the manufacture of OPC, at the same time availability of natural coarse aggregate is getting reduced. Geopolymer binder and recycled aggregates are promising alternatives for OPC and natural coarse aggregates. It is produced by the chemical action of inorganic molecules and made up of Fly Ash, GGBS, fine aggregate, coarse aggregate and an alkaline solution of sodium hydroxide and sodium silicate. 10 M sodium hydroxide and sodium silicate alkali activators are used to synthesis the geopolymer in this study. Recycled aggregates are obtained from the construction demolished waste. The main focus of this work is to find out the mechanical properties of geopolymer concrete of grade G40 when natural coarse aggregate(NCA) is replaced by recycled coarse aggregate in various proportions such as 0%, 10%, 20%, 30%,40% and 50% and also to compare the results of geopolymer concrete made with recycled coarse aggregates(RAGPC) with geopolymer concrete of natural coarse aggregate(GPC) and controlled concrete manufactured with recycled aggregates(RAC) and controlled concrete of natural coarse aggregates(CC) of respective grade. It has been observed that the mechanical properties are enhanced in geopolymer concrete, both in natural coarse aggregate and recycled coarse aggregate up to 30% replacement when it is compared with the same grade of controlled concrete.

On Properties of Recycled Coarse Aggregate from Repeatedly Recycling Waste Concrete

2011 ◽  
Vol 368-373 ◽  
pp. 2185-2188
Author(s):  
Ping Hua Zhu ◽  
Xin Jie Wang ◽  
Jin Cai Feng
Keyword(s):  
Compressive Strength ◽  
Coarse Aggregate ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Fine Aggregate ◽  
Recycled Coarse Aggregate ◽  
Coarse Aggregates ◽  
Recycled Fine Aggregate ◽  
Waste Concrete

The properties of recycled coarsee aggregates from repeatedly recycling waste concrete were determined. In this study, five series of concrete mixtures using coarse and fine natural aggregates were prepared, which have the same objective slump value from 35mm to 50mm and different compressive strengths ranging from 25MPa to 60 MPa. These five concretes were crushed, sieved, washed with water, hot treatmented at 300°C before they were used as recycled aggregates. After that, recycled aggregate concrete (RAC) was produced with an objectively compressive strength of 30MPa, in which the recycled coarse aggregate was used as 30%, 70% and 90% replacements of natural coarse aggregate and recycled fine aggregate as 10%, 20%, and 30% replacements of natural fine aggregate. After that, these recycled concretes were used as second recycled aggregates to produce RAC with the same objectively compressive strength of 30MPa. The physical properties of coarse aggregates including apparent density, water absorption, attached mortar content and crushing value were tested and their mineral characteristics were analyzed. The results showed that the quality of recycled coarse aggregates from twicely recycling waste concrete reached the requirements from structural concrete.

Standardization as a Driving Force of the use of Recycled Coarse Aggregate in Concrete

2013 ◽  
Vol 742 ◽  
pp. 371-378
Author(s):  
Desirée Rodríguez Robles ◽  
Julia García González ◽  
Andrés Juan Valdés ◽  
Julia M. Morán del Pozo ◽  
M. Ignacio Guerra Romero
Keyword(s):  
Construction Industry ◽  
Driving Force ◽  
Building Materials ◽  
Coarse Aggregate ◽  
Environmentally Friendly ◽  
Coarse Fraction ◽  
Construction And Demolition Waste ◽  
Recycled Aggregates ◽  
Demolition Waste ◽  
Recycled Coarse Aggregate

When recycled aggregates are used appropriately, it is possible to obtain good quality, economic and environmentally friendly building materials. The emergence in recent years of the use of recycled materials in the construction industry, specifically in the production of concrete, has met with varying degrees of success due to the barriers that the market for recycled products has still to overcome. Scientific studies have focused on the good properties presented by the coarse fraction of construction and demolition waste (CDW), leading to the formulation of various international recommendations which, although still insufficient, provide a stimulus to the use of recycled aggregates in concrete.

scholarly journals Concrete produced with recycled aggregates

2012 ◽  
Vol 5 (5) ◽  
pp. 692-701 ◽  
Author(s):  
J. J. L. Tenório ◽  
P. C. C. Gomes ◽  
C. C. Rodrigues ◽  
T. F. F. de Alencar
Keyword(s):  
Coarse Aggregate ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Hardened Concrete ◽  
Specific Mass ◽  
River Sand ◽  
Recycled Coarse Aggregate ◽  
Coarse Aggregates ◽  
Natural Aggregates

This paper presents the analysis of the mechanical and durable properties of recycled aggregate concrete (RAC) for using in concrete. The porosity of recycled coarse aggregates is known to influence the fresh and hardened concrete properties and these properties are related to the specific mass of the recycled coarse aggregates, which directly influences the mechanical properties of the concrete. The recycled aggregates were obtained from construction and demolition wastes (CDW), which were divided into recycled sand (fine) and coarse aggregates. Besides this, a recycled coarse aggregate of a specific mass with a greater density was obtained by mixing the recycled aggregates of the CDW with the recycled aggregates of concrete wastes (CW). The concrete was produced in laboratory by combining three water-cement ratios, the ratios were used in agreement with NBR 6118 for structural concretes, with each recycled coarse aggregates and recycled sand or river sand, and the reference concrete was produced with natural aggregates. It was observed that recycled aggregates can be used in concrete with properties for structural concrete. In general, the use of recycled coarse aggregate in combination with recycled sand did not provide good results; but when the less porous was used, or the recycled coarse aggregate of a specific mass with a greater density, the properties of the concrete showed better results. Some RAC reached bigger strengths than the reference concrete.

scholarly journals Concrete performance evaluation of coarse aggregate replacement by civil construction waste

2020 ◽  
Vol 24 ◽  
pp. e52
Author(s):  
Juliane Patricia Oliveira ◽  
Carlos Henrique Dos Santos ◽  
Maria Lúcia Okumura ◽  
Natália Ueda Yamaguchi
Keyword(s):  
Natural Resources ◽  
Coarse Aggregate ◽  
Construction And Demolition Waste ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Construction Sector ◽  
Waste Generation ◽  
Demolition Waste ◽  
The Sustainable Development ◽  
Recycled Coarse Aggregate

The construction sector is considered a major generator of environmental impacts due to the high consumption of natural resources and waste generation. Thus, this article aims to evaluate the performance of a concrete produced by the partial and total replacement of natural coarse aggregate by recycled coarse aggregate, derived from the concrete residue of buildings and demolitions. The study was made by comparing the compressive strength and absorption of three different concrete traces, keeping the water/cement factor of 0.60 and changing only the proportions of recycled coarse aggregate between 0%, 50% and 100%. The results showed that the higher the percentage of substitution, the greater the water absorption and the lower the resistance results concrete compression. This result was obtained due to the lighter characteristic of the recycled aggregate compared to the natural aggregate. It was concluded that the concrete produced with recycled aggregates could be used in nonstructural functions, giving an adequate destination to the construction and demolition waste and consequently reducing the extraction and consumption of natural resources and contributing for the sustainable development.

Experiment on Improving Performance of Recycled Coarse Aggregate from Waste Concrete

2012 ◽  
Vol 174-177 ◽  
pp. 198-201
Author(s):  
Li Sun ◽  
Ying Wei Yun
Keyword(s):  
Natural Resources ◽  
Cement Paste ◽  
Coarse Aggregate ◽  
Environmental Issues ◽  
Recycled Aggregates ◽  
Aggregate Concrete ◽  
Ordinary Concrete ◽  
Recycled Coarse Aggregate ◽  
Coarse Aggregates ◽  
Waste Concrete

Recently recycled coarse aggregate concrete tends to be developed by using waste concrete considering environmental issues and conserving natural resources. However, performances of recycled coarse aggregate concrete are relative low compared with ordinary concrete due to the differences between recycled coarse aggregates and natural ones. In this research, developed mill is used to shuck the cement paste adhering on the surface of coarse aggregates to obtain shucking recycled coarse aggregates. Experimental results demonstrate that the performances of shucking recycled aggregates and concerned concrete are both improved.

scholarly journals Effect of Recycled Coarse Aggregate and Bagasse Ash on Two-Stage Concrete

Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 556
Author(s):  
Muhammad Faisal Javed ◽  
Afaq Ahmad Durrani ◽  
Sardar Kashif Ur Rehman ◽  
Fahid Aslam ◽  
Hisham Alabduljabbar ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Coarse Aggregate ◽  
Construction Material ◽  
Strength Reduction ◽  
Recycled Aggregate ◽  
Two Stage ◽  
Conventional Concrete ◽  
Recycled Coarse Aggregate ◽  
Coarse Aggregates

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.

scholarly journals Effect of Recycled Coarse Aggregates in Properties of Concrete

2008 ◽  
Vol 3 (4) ◽  
pp. 130-137 ◽  
Author(s):  
R Kumutha ◽  
K Vijai
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Modulus Of Elasticity ◽  
Coarse Aggregate ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Split Tensile Strength ◽  
Coarse Aggregates ◽  
The Cost

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.

scholarly journals Sustainability of Construction Aggregates in Kuwait

2019 ◽  
Vol 2 (4) ◽  
pp. 406
Author(s):  
Sharifa Al-Fadala
Keyword(s):  
Construction Industry ◽  
United Arab Emirates ◽  
Coarse Aggregate ◽  
Waste Utilization ◽  
Recycled Aggregates ◽  
Environmental Pressures ◽  
Coarse Aggregates ◽  
Constituent Material ◽  
Construction And Demolition Wastes ◽  
Local Construction

Kuwait is facing a current construction boom with projects worth of more than USD188bn. The huge infrastructure spending plan of Kuwait is reflected with a growing demand of concrete as concrete is the most commonly used building material in the local construction. At the present, the quarrying of coarse aggregate which is a main concrete constituent material is banned in Kuwait since 1997 and construction industry depends on the imported coarse aggregates from neighbouring sources such as United Arab Emirates and Iran. Kuwait is also interested in challenging the growing concern of an effective environmental management of water, land and atmosphere to achieve a sustainable civilization. The increasingly environmental pressures coupled with the limited available economical resources are causing the decision making authorities to consider the practice of recycling and waste utilization. This paper presents Kuwait Institute for Scientific Research (KISR) efforts to investigate sustainable sources of coarse aggregate for construction industry from waste. The first sustainable source investigated is the production of synthetic lightweight aggregates utilizing combinations of argillaceous indigenous and waste materials, and the second is recycled aggregates from construction and demolition wastes. The potential of the two sustainable sources of construction aggregates are presented and the needed steps for real industrial application are addressed.

scholarly journals Quality Improvement of Recycled Aggregate Concrete using Six Sigma DMAIC Methodology

2020 ◽  
Vol 5 (6) ◽  
pp. 1409-1419
Author(s):  
Suhas Vijay Patil ◽  
Balakrishna Rao K. ◽  
Gopinatha Nayak
Keyword(s):  
Six Sigma ◽  
Coarse Aggregate ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Lower Grade ◽  
Test Results ◽  
Aggregate Concrete ◽  
Recycled Coarse Aggregate ◽  
Concrete Mix

Recycled aggregates (RA) are obtained from construction and demolished waste, laboratory crushed concrete and concrete waste at RMC plants. The concrete made from recycled aggregate is known as recycled aggregate concrete. The use of recycled aggregate is very beneficial to the environment in civil works. Its usage also helps in financial saving as the cost of transportation and production energy cost of natural coarse aggregate (NCA) is reduced. In India, the recycled aggregate application in lower grade concrete work is observed. However, the effect of recycled aggregate on the strength and durability of concrete restricts its use in higher-grade work. This paper presents a series of tests carried out on recycled coarse aggregate (RCA) and recycled coarse aggregate concrete (RCAC) and test results are compared with the NCA and parent concrete made from NCA. Tests were carried out as per IS code and concrete was prepared using a two-stage mixing approach in the concrete mix design. M30 concrete mix of four RCAC samples was tested at 28 days of curing and in comparison with parent concrete, it is found that on an average compressive strength is decreased by 12.89% at 28 days curing. Adhered mortar increases the porosity of the recycled aggregate and forms a weak zone between aggregate surface and mortar. In addition, test results showed the defects in recycled aggregate and helped to identify the area where concentration is necessary to improve the quality of recycled aggregate using six sigma DMAIC methodology. Total of 12 defects were found in the process and raw material. Statistical analysis was used to evaluate the performance of all the mix made with RCA.

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