scholarly journals Properties of Cementitious Materials with Recycled Aggregate and Powder Both from Clay Brick Waste

Buildings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 119
Author(s):  
Huixia Wu ◽  
Jianzhuang Xiao ◽  
Chaofeng Liang ◽  
Zhiming Ma

The utilization of recycled brick aggregate (RBA) and recycled brick powder (RBP) in cementitious materials helps the reclamation of clay brick waste in construction and demolition waste. This work studied the properties of cementitious materials with RBA as aggregate and RBP as supplementary cementitious material. The RBA has lower apparent density and higher water absorption than natural aggregate, and RBP with an irregular micro-structure contains high content of silicon and aluminum oxides and possesses excellent pozzolanic activity. Incorporating RBP decreases the fluidity and increases the setting time, but the incorporated RBP improves the pore structure and decreases the average pore diameter of cementitious materials, thereby decreasing the permeability. Utilizing RBA increases the drying shrinkage, while the incorporated RBP decreases the drying shrinkage of cementitious materials; the mortar with 50% RBA and 30% RBP has the lower drying shrinkage than the common mortar without RBA and RBP. Incorporating RBA and high-volume RBP decreases the mechanical strength, while there is no obvious decrease in the mechanical strength for the mortar with 50% RBA and 30% RBP. Moreover, the flexural strength to compressive strength ratio increases with RBA and RBP incorporating. Utilizing RBA increases the water transport, while the water transport properties decrease with the RBP incorporation; incorporating appropriate content of RBA and RBP can obtain the cementitious materials with low permeability. Particularly, a significant decrease in chloride ingress occurs with the substitution of RBP.

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1976 ◽  
Author(s):  
Samuel Roque ◽  
Cinthia Maia Pederneiras ◽  
Catarina Brazão Farinha ◽  
Jorge de Brito ◽  
Rosário Veiga

This paper presents a study of incorporation of two types of construction and demolition waste (CDW) in rendering mortars, as aggregates at 0%, 20%, 50% and 100% (by volume). Recycled concrete aggregate (RCA) and mixed recycled aggregate (MRA) were used. The former is mainly composed of cementitious waste and the latter consists of a mixture of non-segregated wastes. The performance of the cement mortars with recycled aggregates was evaluated through an extensive experimental programme. The analysis comprised workability, mechanical strength, water absorption, shrinkage, open porosity and the evaluation of durability by permeability to water under pressure after an artificial accelerated ageing test. The results are considered positive, although as the incorporation of recycled aggregates (both MRA and RCA) increased the mechanical strength, the modulus of elasticity and bulk density decreased, which leads to the production of lighter mortars that are less susceptible to cracking. The modified mortar with 20% of MRA presented the best performance, in terms of mechanical behaviour.


2020 ◽  
Vol 19 (3) ◽  
pp. 407-421
Author(s):  
Yimmy Fernando Silva ◽  
◽  
David A. Lange ◽  
Silvio Delvasto ◽  
◽  
...  

This paper presents results of an experimental study of a residue of masonry (RM), sampled from a construction and demolition waste (CDW), added as a supplementary cementitious material (SCM) to partially replace up to 50% of Portland cement in the preparation of mortars. The pozzolanic activity (fixed lime and strength activity index), setting time, heat of hydration, the (autogenous and drying) shrinkage and compressive strength tests were carried out. The results show how the RM has a positive activity because the increase of RM replacement level in the mortars generates a lower heat of hydration and autogenous and drying shrinkage. The fixed lime at 28 and 180 days, indicating that the RM exhibits in some degree pozzolanic activity and the Strength Activity Index (SAI) was 77.13% and 84.36% of the compressive strength of 100% OPC mortar at the 7 and 28 days respectively, which conformed to ASTM C311. These results indicate that RM should be considered appropriated for using as a supplementary cementitious material.


Author(s):  
Lia Lorena Pimentel ◽  
Giovanna Falzetta Rizzo ◽  
Ana Elisabete Paganelli Guimarães de Avila Jacintho ◽  
Patrícia Stella Pucharelli Fontanini

abstract: Construction and Demolition waste (CDW) is already used in many European countries as recycled aggregates to produce concrete for structural purposes. In Brazil, its use is still restricted to concretes with no structural function. The consumption of aggregates for the production of concrete is very large, and enabling the use of recycled aggregates in the production of concrete is essential to transform the civil construction industry into a more sustainable one. This work aimed to study the parameters that affect the durability of C30 grade concrete, produced with different types of recycled aggregate. We defined four types of coarse aggregates for carrying out this work: the natural (AN), the concrete (ARCO), the cementitious materials (ARCI) and the treated cementitious materials (ARCI Treated). We adopted 30% substitution content of natural aggregate for recycled aggregates. The treatment of the ARCI aggregate consisted of the application of water and cement solution, aiming to reduce its water absorption capacity. We determine the physical and mechanical characteristics of the concrete, in addition to carrying out indirect measurement tests of durability, by determining the permeability to air, penetration and migration of chloride ions, and determination of the carbonation depth. The results indicate that the concrete using the ARCO type aggregate, produced with 100% crushed concrete, presented characteristics like the reference concrete, indicating the possibility that it can be applied to reinforced concrete structures. As for the ARCI type aggregate, it presented inferior results when compared to the concrete reference for the tests of indirect measurement of durability, however, the concrete displayed good mechanical properties. The concrete produced with the treated ARCI did not perform better than the concrete with ARCI for most of the evaluated characteristics, indicating that the proposed treatment was not adequate.


Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2247
Author(s):  
Fernando da Silva Souza ◽  
José Maria Franco de Carvalho ◽  
Gabriela Grotti Silveira ◽  
Vitória Cordeiro Araújo ◽  
Ricardo André Fiorotti Peixoto

The lack of usable aggregates for civil construction in Rio Branco (capital of Acre, a Federal State in the Amazon region) makes the production and use of recycled aggregates from construction and demolition waste (CDW) an alternative of great interest. In this study, a comprehensive characterization of CDW collected from 24 construction sites of six building types and three different construction phases (structures, masonry, and finishing) was carried out. The fine and coarse recycled aggregates were produced and evaluated in 10 different compositions. The aggregates’ performance was evaluated in four mixtures designed for laying and coating mortars with a total replacement of conventional aggregates and a mixture designed for a C25 concrete with 50% and 100% replacement of conventional aggregates. CDW mortars showed lower densities and greater water retention, initial adhesion, and mechanical strength than conventional mortars. CDW concretes presented lower densities and greater resistance to chloride penetration than conventional concrete, with a small mechanical strength reduction. The recycled CDW aggregates proved to be technologically feasible for safe application in mortars and concrete; for this reason, it is believed that the alternative and proposed methodology is of great interest to the Amazonian construction industry, considering the high costs of raw materials and the need for defining and consolidating a sustainable development model for the Amazon region.


2016 ◽  
Vol 881 ◽  
pp. 346-350 ◽  
Author(s):  
Luzana Leite Brasileiro ◽  
Fátima Maria de Souza Pereira ◽  
Pablo de Abreu Vieira ◽  
José Milton Elias de Matos

Every year, there is a considerable increase in the exploitation of deposits to supply the market for aggregates. On the other hand, so does the production of solid waste from construction and demolition waste (CDW). In 2010 Brazil approved the PNRS (National Policy on Solid Waste), which sets out how the country should have their waste, encouraging recycling and sustainability. As an alternative to the above problem, this paper aims to investigate the feasibility of partial and total replacement of the asphalt concrete aggregates by recycled aggregates from CDW in order to reduce the environmental impacts caused by the operation of quarries and give an adequate final destination the residue produced by man in construction. Were carried out five (05) projects mixture of: the first (parameter of our research) used only natural aggregates (0% CDW) in the second, third and fourth replaced 25%, 50% and 75% respectively of natural aggregate by the recycled aggregate and the fifth and last, used only recycled aggregates (100% CDW). They carried out the characterization of the aggregates by means of physico-chemical and mechanical, analyzing them with reference based on specific standards paving. For mixtures, they calculated the volumetric parameters and performed mechanical tests of tensile strength and stability. The results indicate that the recycled aggregate, in a defined proportion, can replace the natural aggregate in the flexible pavements


Author(s):  
Sharifah Salwa Mohd Zuki ◽  
◽  
Shahiron Shahidan ◽  
Shivaraj Subramaniam ◽  
◽  
...  

This paper discussed the recycled aggregates produced from construction and demolition waste and their utilization in concrete construction. Along with a brief overview of the engineering properties of recycled aggregates, the paper also summarizes the effect and use of recycled aggregates on the properties of fresh and hardened concrete. The recycled aggregates were treated with epoxy resin to reduce the water absorptions with different percentages of resin such as 0%, 25%, 50%, 75%, and 100%. Epoxy resin is widely used in recent years owing to the enhancing of mechanical and durability of the concrete. This research also showed, recycled aggregate concrete are close proximity to normal concrete in terms of split tensile strength, compression strength and wet density. The low usage of resin was obtained good strength concrete compared to high percentage contained treated aggregates due to low bonding between material.


Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4620
Author(s):  
Fan You ◽  
Surong Luo ◽  
Jianlan Zheng ◽  
Kaibin Lin

Using recycled aggregate in concrete is effective in recycling construction and demolition waste. It is of critical significance to understand the fatigue properties of recycled aggregate concrete (RAC) to implement it safely in structures subjected to repeated or fatigue load. In this study, a series of fatigue tests was performed to investigate the compressive fatigue behavior of RAC. The performance of interfacial transition zones (ITZs) was analyzed by nanoindentation. Moreover, the influence of ITZs on the fatigue life of RAC was discussed. The results showed that the fatigue life of RAC obeyed the Weibull distribution, and the S-N-p equation could be obtained based on the fitting of Weibull parameters. In the high cycle fatigue zone (N≥104), the fatigue life of RAC was lower than that of natural aggregate concrete (NAC) under the same stress level. The fatigue deformation of RAC presented a three-stage deformation regularity, and the maximum deformation at the point of fatigue failure closely matched the monotonic stress-strain envelope. The multiple ITZs matched the weak areas of RAC, and the negative effect of ITZs on the fatigue life of RAC in the high cycle fatigue zone was found to be greater than that of NAC.


Author(s):  
Cinthia Maia Pederneiras ◽  
Maria Del Pilar Durante ◽  
Ênio Fernandes Amorim ◽  
Ruan Landolfo da Silva Ferreira

ABSTRACT: The consumption of natural resources and energy increased proportionally with the growth of the world population and its economic level. There was an increasing exponential consumption of natural resources, which implied an increase in environmental impacts. The construction sector is responsible for a very significant production of construction and demolition waste (CDW). Thus, there is a concern in search of a more sustainable final disposal. Many studies have been investigated the development of new materials with the incorporation of recycled aggregates from CDW. This paper presents a study of performance evaluation of concrete blocks produced with CDW. For that purpose, an experimental campaign was performed, including a characterization of the aggregates used. The incorporation of 100% of fine and coarse recycled aggregates. The mixtures were designed according to the condition of the aggregate (dry, washed or saturated). The performance of these blocks was evaluated in terms of mechanical strength and water absorption. Some additional tests were also performed to deeper analyze of the microstructure of these blocks. To assess the durability of the concrete blocks, a full-scale road was built. The results were very positive, since there were no significant differences between the modified concrete blocks and the reference sample (0% of the CDW). The modified block with fine aggregate presented the best performance of all the blocks, concerning mechanical strength. In addition, the performance of concrete blocks with washed recycled aggregates had a better performance compared to the others. The results obtained were satisfactory for the application of the blocks in the streets with low movement and low load.


2018 ◽  
Vol 760 ◽  
pp. 193-198 ◽  
Author(s):  
Kristina Fořtová ◽  
Tereza Pavlů

This paper presents research results of recycled fine aggregate concrete testing. The main aim of this contribution is verification of properties of fine aggregate concrete with partial replacement of fine natural aggregate by recycled masonry aggregate originated from construction and demolition waste. The influence of partial replacement of natural sand to mechanical properties and freeze-thaw resistance is described. The compressive strength and flexural strength were tested at the age of 28 and 60 days and after 25, 50, 75 and 100 freeze-thaw cycles. Partial replacement of natural sand was 0, 25 and 50 % for all these tests. Prismatic specimens were examined.


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