scholarly journals The Influence of Fly Ash on the Compressive Strength of Recycled Concrete Utilizing Coarse Aggregates from Demolition Works

2021 ◽  
Vol 11 (3) ◽  
pp. 7107-7110
Author(s):  
V. T. Phan ◽  
T. H. Nguyen
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Recycled Concrete ◽  
Experimental Results ◽  
Strength Development ◽  
Concrete Aggregate ◽  
Recycled Concrete Aggregate ◽  
Coarse Aggregates ◽  
Natural Aggregates

The compressive strength of recycled concrete with coarse aggregates with and without fly ash was studied in this paper. The recycled concrete was designed to have a compressive strength of Rn=15Mpa. The ratio of conventional aggregates and recycled coarse aggregates was 50-50. Fifteen samples for each recycled concrete aggregate had been cast and were tested 7, 14, and 28 days after curing. The experimental results indicate that the strength development of the two recycled concrete mixes is relatively uniform. Fly ash increased the compressive strength of recycled concrete by 11% for 7-day aged samples. The recycled concrete with fly ash had 7% less compressive strength than the concrete consisting of natural aggregates.

scholarly journals Achieve High Compressive Strength and durability of Concrete Made from Recycled Concrete Aggregate

2019 ◽  
Vol 8 (10) ◽  
pp. 2211-2214
Keyword(s):  
Compressive Strength ◽  
High Strength ◽  
Recycled Concrete ◽  
Concrete Aggregate ◽  
Recycled Concrete Aggregate ◽  
Abrasion Test ◽  
High Compressive Strength ◽  
Coarse Aggregates ◽  
Compressive Strength Test ◽  
Strength And Durability

Growth in the construction industry is growing daily and the demolition of the old structure creates massive quantities of rubbles and from that 30-40% were coarse aggregate. Utilizing of coarse aggregates through recycling helps to give economic and sustainable development. The aim of this study is to achieve high compressive strength with minimum wear effect of new concrete made of recycled concrete aggregate. To achieve aim in this study has been considered high strength of concrete mix i.e.M40, M50 and M60 for compressive strength and for abrasion test, considered mix of M50 and M60. A replacement percentage for the compressive strength test was 0%(normal), 20%, 40%, 60%, and 80% while for abrasion test considering 0%, 20%, 40% and 60% replacement ratio. This research helps to use recycled concrete aggregate in construction sector

Possibilities of Recycled Concrete Aggregate in Cement-Based Flowscreed

2014 ◽  
Vol 897 ◽  
pp. 247-251
Author(s):  
Adam Hubáček ◽  
Luc Boehme ◽  
Iveta Nováková
Keyword(s):  
Mechanical Properties ◽  
Recycled Concrete ◽  
Experimental Results ◽  
Recycled Aggregates ◽  
Partial Replacement ◽  
Concrete Aggregate ◽  
Rheological Characteristics ◽  
Test Results ◽  
Recycled Concrete Aggregate ◽  
Natural Aggregates

This paper presents some test-results of using fine recycled concrete as a partial replacement of natural aggregates in cement-based flowscreed. Special attention is given to describing and studying rheological characteristics and mechanical properties of cement-based flowscreed. Experimental results indicate that it is possible to prepare flowscreed with partial replacement of natural aggregates by recycled aggregates and obtain a quality that meets the requirements. This study was partially connected to the research-project RecyFlowscreed [1].

Strength development of recycled concrete aggregate stabilized with fly ash-rice husk ash based geopolymer as pavement base material

2019 ◽  
Vol 21 (8) ◽  
pp. 2344-2355 ◽  
Author(s):  
Theerapruet Poltue ◽  
Apichat Suddeepong ◽  
Suksun Horpibulsuk ◽  
Wisanukhorn Samingthong ◽  
Arul Arulrajah ◽  
...  
Keyword(s):  
Fly Ash ◽  
Rice Husk ◽  
Rice Husk Ash ◽  
Base Material ◽  
Recycled Concrete ◽  
Strength Development ◽  
Concrete Aggregate ◽  
Recycled Concrete Aggregate ◽  
Pavement Base

scholarly journals Effects of Fly Ash on Mechanical Properties of Concrete

2018 ◽  
Vol 8 (2) ◽  
pp. 35-40 ◽  
Author(s):  
Masoud Zabihi-Samani ◽  
Seyed Payam Mokhtari ◽  
Farzaneh Raji
Keyword(s):  
Fly Ash ◽  
Transport Properties ◽  
Carbon Dioxide Emissions ◽  
Recycled Concrete ◽  
Curing Temperature ◽  
Strength Development ◽  
Concrete Aggregate ◽  
Test Results ◽  
Recycled Concrete Aggregate ◽  
Low Carbon

Abstract Cement is a common and widespread building material over the world. Similarly, carbon dioxide emissions have been significantly increased due to cement production. Alternative low-carbon binders rather than cement have been progressively sought in recent years. Fly ash was found as an available option, since it is being largely disposed annually as a waste material. In this research several studies have been reviewed and recent applications of fly ash on concrete specification, including strength and fracture toughness of green concrete have been perused. Furthermore, transport properties of high volume fly ash after exposure to high temperature and influence of curing temperature on strength development of fly ash-recycled concrete aggregate blends have been investigated. The investigated test results showed that the properties of composites incorporating fly ash depend on the age of the concrete. Test results also revealed that transport properties of concrete increased notably after exposure to 400cº and the results achieved on fly ash-recycled concrete aggregate led to the conclusion that 15% FA is the optimum blend for road stabilization applications.

scholarly journals Properties of Concrete with Recycled Concrete Aggregate Containing Metallurgical Sludge Waste

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1448 ◽  
Author(s):  
Jan Pizoń ◽  
Jacek Gołaszewski ◽  
Mohamed Alwaeli ◽  
Patryk Szwan
Keyword(s):  
Compressive Strength ◽  
Recycled Concrete ◽  
Concrete Aggregate ◽  
Hardened Concrete ◽  
Recycled Concrete Aggregate ◽  
Metallurgical Waste ◽  
Illegal Mining ◽  
Marine Sand ◽  
Sludge Waste ◽  
Natural Aggregates

Sand has been considered to be something of an immeasurable quantity. There are many indications that this view is no longer valid and that the limiting of natural aggregates usage is doubly justified. Firstly, the extraction of natural aggregates is expensive and has a huge impact on the environment. The main issues in sand and gravel mining are the large areas that are affected, ground water level changes, illegal mining, unsuitability of desert and marine sand, and costs of transport. Secondly, metallurgical waste can be used as a substitute for natural aggregates. This is doubly beneficial—the waste is recycled and the use of natural aggregates is reduced. Waste is stored in landfills that take up large areas and there is also the possibility of ground and groundwater pollution by hazardous compounds. The research presented in this article focuses on the technological conditions of using metallurgical waste in its original form and as a component of recycled concrete aggregate (RCA). The use of metallurgical sludge waste or crushed or round RCA to produce concrete deteriorates the consistency and does not significantly affect the air content and density of the concrete mix. RCA lowers the density of hardened concrete. Metallurgical sludge waste or RCA usage adversely affect the absorbability and permeability of concrete. Concrete containing metallurgical sludge waste is of higher compressive strength after 7 and 28 days, with up to 60% of waste as a sand replacement. RCA concrete achieved higher compressive strength also.

scholarly journals Physical, Deformation, and Stiffness Properties of Recycled Concrete Aggregate

2021 ◽  
Vol 13 (8) ◽  
pp. 4245
Author(s):  
Katarzyna Gabryś ◽  
Emil Soból ◽  
Wojciech Sas
Keyword(s):  
Recycled Concrete ◽  
Experimental Program ◽  
Concrete Aggregate ◽  
Test Results ◽  
Recycled Concrete Aggregate ◽  
Granulometric Analysis ◽  
Stiffness Properties ◽  
Grain Distribution ◽  
Natural Aggregates ◽  
Critical Reduction

The construction sector is currently struggling with the reuse of waste originating from the demolition and modernization of buildings and roads. Furthermore, old buildings are gradually being replaced by new structures. This brings a significant increase of concrete debris to waste landfills. To prevent this, many studies on the possibilities of recycling concrete, known as recycled concrete aggregate (RCA), have been done. To broaden the applicability of reused concrete, an understanding of its properties and engineering behavior is required. A difficulty in sustainable, proper management of RCA is the shortage of appropriate test results necessary to assess its utility. For this reason, in the present study, the physical, deformation, and stiffness properties of RCA with gravely grain distribution were analyzed carefully in the geotechnical laboratory. To examine the mentioned properties, an extensive experimental program was planned, which included the following studies: granulometric analysis, Proctor and oedometer tests, as well as resonant column tests. The obtained research results show that RCA has lower values of deformation and stiffness parameters than natural aggregates. However, after applying in oedometer apparatus repetitive cycles of loading/unloading/reloading, some significant improvement in the values of the parameters studied was noticed, most likely due to susceptibility to static compaction. Moreover, some critical reduction in the range of linear response of RCA to dynamic loading was observed.

Recycling of Waste Concrete and Fly Ash for Recycled Aggregate Concrete: Fundamental Characteristics Evaluation

2009 ◽  
Vol 620-622 ◽  
pp. 255-258 ◽  
Author(s):  
Cheol Woo Park
Keyword(s):  
Fly Ash ◽  
Recycled Concrete ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Experimental Program ◽  
Concrete Aggregate ◽  
Fine Aggregate ◽  
Recycled Concrete Aggregate ◽  
Aggregate Concrete ◽  
Waste Concrete

As the amount of waste concrete has been increased and recycling technique advances, this study investigates the applicability of recycled concrete aggregate for concrete structures. In addition fly ash, the industrial by-product, was considered in the concrete mix. Experimental program performed compressive strength and chloride penetration resistance tests with various replacement levels of fine recycled concrete aggregate and fly ash. In most case, the design strength, 40MPa, was obtained. It was known that the replacement of the fine aggregate with fine RCA may have greater influence on the strength development rather than the addition of fly ash. It is recommended that when complete coarse aggregate is replaced with RCA the fine RCA replacement should be less than 60%. The recycled aggregate concrete can achieve sufficient resistance to the chloride ion penetration and the resistance can be more effectively controlled by adding fly ash. It I finally conclude that the recycled concrete aggregate can be successfully used in the construction field and the recycling rate of waste concrete and flay ash should be increased without causing significant engineering problems.

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