CONSTRUCTION POTENTIAL OF RECYCLED MASONRY FOR LIGHTWEIGHT CONCRETE

2015 ◽  
Vol 2 (1) ◽  
Author(s):  
Daniela Ionescu ◽  
Bandita Mainali ◽  
Joe Petrolito ◽  
Haider Al Abadi ◽  
Simon Davies ◽  
...  
Keyword(s):  
Lightweight Concrete ◽  
Raw Materials ◽  
Normal Weight ◽  
Production Costs ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Building Industry ◽  
Lightweight Aggregates ◽  
Natural Aggregates ◽  
Recycled Masonry

A sustainable and developing building industry requires large quantities of raw materials such as aggregates and crushed rocks. However, sourcing natural aggregates is becoming more problematic due to environmental impacts. Hence, the use of secondary materials, such as recycled aggregate can reduce the amount of natural aggregates required. Lightweight concrete is frequently used by the building industry, and it is commonly produced with natural lightweight aggregates such as scoria, which results in high production costs. Preliminary tests on recycled aggregates showed that recycled masonry has a similar specific gravity as scoria and relatively good strength. Hence, crushed masonry can be used to replace natural lightweight aggregates. This paper discusses the use of partial or total replacement of normal-weight aggregates with recycled lightweight aggregates, and its effects on the strength and elastic properties of concrete. It is shown that concrete mixes with recycled aggregates generate comparable results to mixes with scoria, but at lower production costs.

Structural Lightweight Aggregate Concrete by Incorporating Solid Wastes as Coarse Lightweight Aggregate

2015 ◽  
Vol 749 ◽  
pp. 337-342 ◽  
Author(s):  
Muhammad Aslam ◽  
Payam Shafigh ◽  
Mohd Zamin Jumaat
Keyword(s):  
Oil Palm ◽  
Lightweight Concrete ◽  
Negative Impact ◽  
Raw Materials ◽  
Lightweight Aggregate ◽  
Normal Weight ◽  
Lightweight Aggregate Concrete ◽  
Lightweight Aggregates ◽  
Aggregate Concrete ◽  
Structural Lightweight Aggregate Concrete

Structural lightweight aggregate concrete offers several benefits as compared to the normal weight concrete. Most common methods of producing structural lightweight concrete is by using artificial lightweight aggregates. However, the cost of the production of artificial lightweight aggregates is high due to energy and raw materials consumption. The use of waste and by-product materials as lightweight aggregate in concrete can provide a better solution to reducing the negative impact of the concrete industry. This paper reports an investigation to produce structural lightweight aggregate concrete by utilizing the locally available solid waste materials, namely oil palm shell (OPS) and oil-palm-boiler clinkers (OPBC) as coarse lightweight aggregates. Two different mix proportions were studied. In the first concrete mix, just OPS was used as coarse aggregate. However, 40% of OPS (by volume) of the first mix was replaced with OPBC in the second mix. The test results showed that by replacing OPS with OPBC, it directly affects the characteristics of the lightweight concrete. The 28-days compressive strength of the blended coarse lightweight aggregate concrete was significantly increased compared to OPS concrete.

scholarly journals Construction and Demolition Waste As Recycled Aggregate for Environmentally-Friendly Concrete Paving.

2021 ◽  
Author(s):  
Manuel Contreras Llanes ◽  
Maximina Romero Pérez ◽  
Manuel Jesús Gázquez González ◽  
Juan Pedro Bolívar Raya
Keyword(s):  
Tensile Strength ◽  
Reference Sample ◽  
Production Costs ◽  
Construction And Demolition Waste ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Demolition Waste ◽  
Natural Sand ◽  
Natural Aggregates ◽  
Sand And Gravel

Abstract Recycled aggregates (RA) from construction and demolition waste (CDW) instead of natural aggregates (NA) was analysed in the manufacture of new eco-friendly concrete. Fine (FRA) and coarse (CRA) recycled aggregates were used in different percentages as substitutes of natural sand and gravel, respectively. The results revealed that the use of RA in percentages of up to 50 wt.% are feasible. Additionally, RA were used to produce paving blocks in accordance with industrial requirements. Thus, values of water absorption lesser than 6% and tensile strength upper than 3.6 MPa were obtained, which are similar to those of a reference sample. These results were achieved by reducing the incorporation of cement, thereby saving production costs and minimizing environmental impact.

scholarly journals On the Possibility of Using Recycled Mixed Aggregates and GICC Thermal Plant Wastes in Non-Structural Concrete Elements

2019 ◽  
Vol 11 (3) ◽  
pp. 633 ◽  
Author(s):  
Carlos Rodríguez ◽  
Isidro Sánchez ◽  
Isabel Miñano ◽  
Francisco Benito ◽  
Marta Cabeza ◽  
...  
Keyword(s):  
Fly Ash ◽  
Coarse Fraction ◽  
Production Costs ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Chloride Ingress ◽  
Structural Concrete ◽  
Construction And Demolition Wastes ◽  
Concrete Production ◽  
Natural Aggregates

Industrial wastes are often used as aggregate in concrete production to promote a more sustainable construction and to reduce production costs. This article presents the results of an experimental campaign on the influence of replacing natural aggregate with several construction and demolition wastes (C&DW) as recycled aggregate, as well as the use of fly ash and slag, wastes produced in Gas Incinerator Combined Cycle (GICC) thermal power plants, in the mix design of non-structural concrete. Different percentages of natural aggregates were substituted with recycled aggregates either coming from construction and demolition wastes, or from the coarse fraction of the slags from thermic plants in the manufacture of concrete. The mechanical properties, capillary water absorption, density, carbonation, chloride ingress and sulphate resistance have been tested. The results show a decrease in properties when C&DW are used. Fine fraction of slag and fly ash has an important advantage, and can even improve the long term properties of concrete prepared with natural aggregates. Coarse fraction of slag as a recycled aggregate generally improves most of the properties of manufactured concretes.

scholarly journals Construction and demolition waste as recycled aggregate for environmentally friendly concrete paving

2021 ◽  
Author(s):  
Manuel Contreras Llanes ◽  
Maximina Romero Pérez ◽  
Manuel Jesús Gázquez González ◽  
Juan Pedro Bolívar Raya
Keyword(s):  
Reference Sample ◽  
Production Costs ◽  
Construction And Demolition Waste ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Demolition Waste ◽  
Natural Sand ◽  
Limit Values ◽  
Natural Aggregates ◽  
Sand And Gravel

AbstractRecycled aggregates (RA) from construction and demolition waste (CDW) instead of natural aggregates (NA) were analysed in the manufacture of new eco-friendly concrete. Fine (FRA) and coarse (CRA) recycled aggregates were used in different percentages as substitutes of natural sand and gravel, respectively. The results revealed that the use of RA in percentages of up to 50 wt.% is feasible. Additionally, RA were used to produce paving blocks in accordance with industrial requirements. Thus, values of water absorption lesser than 6.0% and tensile strength upper than 3.6 MPa were obtained, which are similar to those of a reference sample and within the limit values established by the regulations. These results were achieved by reducing the incorporation of cement, thereby saving production costs and minimizing environmental impact.

scholarly journals A Review on Alkali-Silica Reaction Evolution in Recycled Aggregate Concrete

Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2625 ◽  
Author(s):  
Miguel Barreto Santos ◽  
Jorge De Brito ◽  
António Santos Silva
Keyword(s):  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Mitigation Measures ◽  
Alkali Silica Reaction ◽  
Aggregate Concrete ◽  
Reactive Silica ◽  
Natural Aggregates ◽  
Exposure Conditions ◽  
Lack Of Knowledge

Alkali-silica reaction (ASR) is one of the major degradation causes of concrete. This highly deleterious reaction has aroused the attention of researchers, in order to develop methodologies for its prevention and mitigation, but despite the efforts made, there is still no efficient cure to control its expansive consequences. The incorporation of recycled aggregates in concrete raises several ASR issues, mainly due to the difficult control of the source concrete reactivity level and the lack of knowledge on ASR’s evolution in new recycled aggregate concrete. This paper reviews several research works on ASR in concrete with recycled aggregates, and the main findings are presented in order to contribute to the knowledge and discussion of ASR in recycled aggregate concrete. It has been observed that age, exposure conditions, crushing and the heterogeneity source can influence the alkalis and reactive silica contents in the recycled aggregates. The use of low contents of highly reactive recycled aggregates as a replacement for natural aggregates can be done without an increase in expansion of concrete. ASR expansion tests and ASR mitigation measures need to be further researched to incorporate a higher content of recycled aggregates.

scholarly journals Effect of Recycled Aggregates on the Energy Dissipation Capacity of RC Beam subjected to Reverse Cyclic Flexural Loading

2021 ◽  
Vol 40 (1) ◽  
pp. 140-151
Author(s):  
Muhammad Rizwan Riaz ◽  
Rashid Hameed ◽  
Usman Akmal ◽  
Asad Ali Gillani ◽  
Muhammad Ilyas
Keyword(s):  
Energy Dissipation ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Rc Beam ◽  
Rc Beams ◽  
Aggregate Concrete ◽  
Flexural Loading ◽  
Energy Dissipation Capacity ◽  
Natural Aggregates

The energy dissipation capacity of concrete is an important aspect for a Reinforced Concrete (RC) structure to be seismically resistant. Various types of concrete incorporating sustainable materials are being developed these days such as recycled aggregate concrete. Determination of energy dissipation capacity of such new types of concrete is of great importance for their application in RC structures which are to be constructed in seismically active areas. In this regard, the experimental study presented in this contribution investigated the energy dissipation capacity of RC beams constructed using recycled aggregate concrete and subjected to three different deflection amplitude levels of reverse cyclic flexural loading. For this purpose, a total of 20 RC beams of cross section 75 x 150 mm and length of 1350 mm were cast using five different concrete compositions and tested. Among five different concrete compositions, one was control concrete containing 100% natural aggregates while the remaining four compositions were of recycled aggregate concrete containing natural and recycled aggregates. Four replacement levels (25%, 50%, 75%, and 100%) of natural aggregates with recycled aggregates were examined. Results indicated that the amplitude level of imposed deflection is an important factor which influenced the value of energy dissipated by RC beams. Further, results showed that RC beam constructed using recycled aggregate concrete containing 25% recycled aggregates exhibited energy dissipation capacity similar to or even better than that of control RC beam containing 100% natural aggregates.

scholarly journals Appraisal of Processing Techniques for Recycled Aggregates in Concrete

2019 ◽  
Vol 8 (6) ◽  
pp. 1661-1665 ◽  
Keyword(s):  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Bacterial Suspension ◽  
Mechanical Method ◽  
Treatment Techniques ◽  
Chemical Admixture ◽  
Surface Permeability ◽  
Natural Aggregates ◽  
Processing Techniques

Due to depletion of natural aggregates the need for the usage of recycled aggregate in concrete has gained significance. In this regard, the present study is an attempt to evaluate the performance of M20 grade of concrete made with 100% recycled aggregate processed using various techniques. Handpicked aggregate from concrete rubble is used to prepare recycled aggregate concrete. The use of chemical admixture is mandatory to compensate the extra water (3 to 6%) required by the RCA (Recycled Aggregates). RCA treated with calcite mineral precipitating bacterial suspension enhances its surface permeability. RCA exposed to different acid concentrations improved the surface of the aggregate with the removal of the loosely adhered mortar. In thermal – mechanical method the recycled aggregates from rubble are heated in microwave to 300°C to remove adhered mortar from the aggregate and placed in a rotating drum containing iron balls. In chemical– mechanical method the recycled aggregate is exposed to Na2So4 and is subjected to freeze-thaw cycles to create mechanical to separate adhered mortar from RCA. In acid soaking beneficiation method the mortar around RCA is removed by immersing them in 5% HCl and H2SO4 for 24 hours. All the above mentioned recycled aggregate processing techniques are however to be tested in full scale to study the efficiency of these treatment techniques. Compressive strength and water absorption capacities of various concrete samples made with recycled aggregate prepared using above discussed processing techniques are evaluated.

scholarly journals A Review on Geopolymer RCC Beams made with Recycled Coarse Aggregate

2020 ◽  
Vol 184 ◽  
pp. 01095
Author(s):  
T Srinivas. ◽  
G Abhignya. ◽  
N.V Ramana Rao.
Keyword(s):  
Coarse Aggregate ◽  
Rice Husk Ash ◽  
Concrete Beams ◽  
Raw Materials ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Geopolymer Concrete ◽  
Literature Study ◽  
Conventional Concrete ◽  
Day By Day

In present day scenario, concrete construction is rapidly increasing for different uses and aspects irrespective of the economy and its usage. Due to this imbalanced usage of economy, scarcity of raw materials increasing day by day and environment is getting affected due to manufacturing of cement. This study has been done how to reduce environmental pollution by using different kind of bi product materials in replacement to conventional concrete, which is made up of OPC. The cement can be replaced with fly ash; GGBS, rice husk ash etc, aggregates are being partially replaced with recycled aggregates which come from demolished structures and alkaline liquids such as sodium silicates and sodium hydroxide can be used in concrete, which is called geopolymer concrete. Literature review has been carried out to find the optimum content of aggregates to be replaced and the flexure behavior of the beams is being evaluated. From the literature study, it has been identified that the optimum compressive strength is achieved at 30% replacement of recycled aggregate and ductility natures of both Geopolymer and conventional concrete beams are almost similar.

scholarly journals Performance of Recycled Aggregate Concrete for M25 Grade Concrete

2019 ◽  
Vol 9 (2) ◽  
pp. 4694-4700
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Recycled Concrete ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Aggregate Concrete ◽  
Inorganic Particles ◽  
Natural Aggregates

Recycled aggregates (RCA) are the aggregates which are made up of crushed, inorganic particles that are obtained from the construction demolition debris. Now a day’s protection of environment is the ultimate challenge to the society. So the usage of RCA’s is the best alternative for the aggregates which are obtained naturally in the construction activity. The scope of using these recycled concrete aggregates is increasing day by day. It reduces the cost effectively as we are using waste concrete as recycled aggregates. The main focus of this paper is to use find the strength qualities of recycled aggregates so as to use it as an alternative for the natural aggregates in high strength concrete for various construction activities. Comparison of workability, compressive strength, tensile strength, elastic modulus and flexural strength of recycled aggregate concrete is made with natural aggregate concrete. Here M25 grade concrete is taken and the natural aggregates were replaced with recycled aggregates in various percentages of 0%, 25%, 50%, 75% and 100%. The mix design for these replacement ratios are done by using code of IS 10262-2009. In order to determine the properties which were mentioned above a total of 60 cubes, 10 beams and 40 cylinders were casted. The compressive strength and tensile strength of RCA concrete have been determined for 7 days and 28 days where as the modulus of elasticity and the flexural strength of RCA concrete are determined after curing for the period of 28 days. The tests done on RCA concrete are compared with concrete which is obtained by natural aggregates As per IS codification the parameters which were determined are reducing moderately as the amount of aggregates which are recycled is being raised

scholarly journals Experimental Characterization of Recycled Aggregate Concrete

2019 ◽  
Vol 303 ◽  
pp. 05004
Author(s):  
Khaoula NAOUAOUI ◽  
Azzeddine BOUYAHYAOUI ◽  
Toufik CHERRADI
Keyword(s):  
Compressive Strength ◽  
Developed Countries ◽  
Tourism Industry ◽  
Recycled Concrete ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Aggregate Concrete ◽  
Different Types ◽  
Natural Aggregates

The field of construction is evolving rapidly over the last decade. This is justified by the evolution of human activity in various fields mainly tourism, industry … and the aging of several buildings which implies a renovation or a demolition/re-construction. These construction activities involve a large need for aggregates for new construction and a large tonnage of waste from demolitions. In order to remedy this, various stakeholders in the field (suppliers, cement works, research centers, etc.) have valued recycled aggregate concrete (RAC). Recycled aggregates concrete is considered a new type of concrete based on the use of aggregates retrieved from the demolished structures instead of natural aggregates. This replacement affects, for sure, the characteristics of the concrete produced specially the mechanical properties. Developed countries have made a great progress in normalizing the use of recycled aggregates (RA) in concrete implementation as a result of many studies done since 80’s. In Morocco, recycled aggregates do not have any specific standards, and is used mainly in roads and pavements construction. Even if it’s not normalized this use is not recent, in 1999 during the rehabilitation of the expressway road of Casablanca which was severely damaged on both channels, the authorities have opted for the reuse of aggregates instead of reloading the existing pavement with a new one. The study is based on the use of recycled concrete crushed from an old building in Rabat- Morocco as aggregates and compared it with naturel aggregates from Morocco to determinate the effect of this replacement on several characteristics of concrete. This article is aiming to investigate experimentally the effect of RA in concrete using different replacement levels, different types of adjuvant and different percentages of it. The results show that over 30% of replacement, the compressive strength decreases considerably for basic concrete. In order to increase the compressive strength for the RAC with a percentage of replacement over 50%, we used different types of additives (Plasticizer, superplasticizer and new generation superplasticizer) and different percentage of it (0.5%, 1% and 1.5%): We concludes that, for our case, the add of plasticizer gives the best result and that the 1% replacement is the optimum percentage. The tests done on RCA made by plasticizer with different replacement level confirm the results without plasticizer: Compressive strength decreases when the replacement percentage increases.

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