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Zhaobin Xie - One of the best experts on this subject based on the ideXlab platform.

  • performance enhancement of Recycled Concrete Aggregate a review
    Journal of Cleaner Production, 2016
    Co-Authors: Caijun Shi, Yake Li, Wengui Li, Linlin Chong, Jiake Zhang, Zhaobin Xie
    Abstract:

    Abstract Recycled Concrete Aggregate differ from natural Aggregate as the former contains hardened cement mortar. The adhered cement mortar on Recycled Concrete Aggregate has higher porosity and water absorption and lower strength than natural Aggregate do. It has negative effects on the mechanical properties and durability of fresh and hardened Concrete made with Recycled Concrete Aggregate. Therefore, it will facilitate the applications of Recycled Concrete Aggregate if the adhered cement mortar can be enhanced. Removing and strengthening the adhered mortar are the two main methods for enhancing the properties of Recycled Concrete Aggregate. This paper reviews the published enhancement methods for Recycled Concrete Aggregate, and points out their advantages and disadvantages so as to facilitate the selection and further development of suitable enhancement methods for Recycled Concrete Aggregate. It suggests that carbonation treatment is an efficient and feasible method for improving the mechanical properties and durability of Recycled Concrete Aggregate. Carbonation treatment of Recycled Concrete Aggregate is not only an efficient way for enhancing the properties of Recycled Concrete Aggregate, but also an environmental friendly approach.

  • influence of carbonated Recycled Concrete Aggregate on properties of cement mortar
    Construction and Building Materials, 2015
    Co-Authors: Jiake Zhang, Caijun Shi, Yake Li, Zhaobin Xie, Xiaoying Pan, Chi Sun Poon
    Abstract:

    This work investigated the effect of carbon dioxide treatment of Recycled Concrete Aggregate (RCA) on the performance of RCA and RCA mortar. The results indicated that carbonation increased the apparent density, and reduced both water absorption and the crushing value of the RCA. The flowability and compressive strength of the RCA mortar were lower than those of natural sand mortar. However, the properties of mortar made with carbon dioxide treated RCA were very similar to those of natural sand mortar. Compared with the mortar made of un-carbonated RCA, the mortar made with carbonated RCA showed increased autogenous shrinkage, reduced drying shrinkage, water absorption, and chloride migration coefficient. Scanning electron microscope (SEM) examination on the interfacial transition zone (ITZ) in the RCA and RCA mortar found that carbonation treatment of RCA not only improved the original ITZ in the RCA, but also improved the newly formed ITZ in the RCA mortar.

Chi Sun Poon - One of the best experts on this subject based on the ideXlab platform.

  • sustainable design of pervious Concrete using waste glass and Recycled Concrete Aggregate
    Journal of Cleaner Production, 2019
    Co-Authors: Jianxin Lu, Pingping He, Chi Sun Poon
    Abstract:

    Abstract This study designed an eco-friendly pervious Concrete (PC) product using waste glass cullet (WGC) and Recycled Concrete Aggregate (RCA) by dry-mixed compaction technique. The mechanical properties, water permeability behavior and related pore structure characteristics, thermal conductivity of the PCs were determined. The experimental results showed that the use of silica fume in the cement paste was effective to compensate for the low compressive strength of the PCs due to the use of narrowed graded Aggregates without the incorporation of fine particles (less than 2.36 mm). Although the incorporation of Recycled Aggregates (i.e. WGC and RCA) into the PCs led to reductions in compressive strength, the water permeability of the PCs was improved, especially for the PCs prepared with WGC, as the use of WGC was conducive to improving the water permeability due to the negligible water absorption nature and smooth surface of glass cullet. Another encouraging result indicated that the PCs comprising 50% WGC as the fine Aggregate and 50% RCA as the coarse Aggregates could achieve satisfactory strength and permeability, which could largely meet the requirement of the standard (JIS A 5371) for permeable pedestrian pavers. The appropriate blending of the selected size of WGC (2.36–5 mm) and RCA (5–10 mm) to produce a desirable pore structure in the PCs were responsible for the good performance. In addition, the low thermal conductivity of the produced PCs provided an opportunity to use the PC as partition block materials for saving energy consumption of buildings.

  • influence of carbonated Recycled Concrete Aggregate on properties of cement mortar
    Construction and Building Materials, 2015
    Co-Authors: Jiake Zhang, Caijun Shi, Yake Li, Zhaobin Xie, Xiaoying Pan, Chi Sun Poon
    Abstract:

    This work investigated the effect of carbon dioxide treatment of Recycled Concrete Aggregate (RCA) on the performance of RCA and RCA mortar. The results indicated that carbonation increased the apparent density, and reduced both water absorption and the crushing value of the RCA. The flowability and compressive strength of the RCA mortar were lower than those of natural sand mortar. However, the properties of mortar made with carbon dioxide treated RCA were very similar to those of natural sand mortar. Compared with the mortar made of un-carbonated RCA, the mortar made with carbonated RCA showed increased autogenous shrinkage, reduced drying shrinkage, water absorption, and chloride migration coefficient. Scanning electron microscope (SEM) examination on the interfacial transition zone (ITZ) in the RCA and RCA mortar found that carbonation treatment of RCA not only improved the original ITZ in the RCA, but also improved the newly formed ITZ in the RCA mortar.

  • paving blocks made with Recycled Concrete Aggregate and crushed clay brick
    Construction and Building Materials, 2006
    Co-Authors: Chi Sun Poon, Dixon Chan
    Abstract:

    Abstract Clay brick generated from construction sites is usually delivered to landfills for disposal. With the limited landfill space in Hong Kong, there is an immediate need to explore the possible use of crushed clay brick as a new civil engineering material. In Hong Kong, government specifications promote the use of paving blocks made with 70–100% Recycled Concrete Aggregate in order to facilitate the recycling of construction and demolition (C&D) waste. This paper presents a recent study at the Hong Kong Polytechnic University on the investigation of blending Recycled Concrete Aggregate and crushed clay brick as Aggregates in the production of paving blocks. The results indicated that the incorporation of crushed clay brick reduced the density, compressive strength and tensile strength of the paving blocks. Due to the high water absorption of crushed clay brick particles, the water absorption of the resulting paving blocks were higher than that of the paving blocks that did not incorporate crushed clay brick. Although it was found that crushed clay brick impaired the quality of the resulting paving blocks to a certain extent, the paving blocks using 50% crushed clay brick met the minimum requirements specified by AS/NZS 4455 and ETWB of Hong Kong (Grade B) for pedestrian areas. Furthermore, it was feasible to produce paving blocks prepared with 25% crushed clay brick that satisfied the compressive strength requirement for paving blocks (Grade B) prescribed by ETWB of Hong Kong for trafficked area.

Nicolas Roquet - One of the best experts on this subject based on the ideXlab platform.

  • Recycled Concrete Aggregate attrition during mixing new Concrete
    Construction and Building Materials, 2016
    Co-Authors: Jaime Moreno Juez, Bogdan Cazacliu, Alexis Cothenet, Riccardo Artoni, Nicolas Roquet
    Abstract:

    In this work, the Recycled Concrete Aggregate (RCA) friability during mixing was studied in order to better understand the evolution of this material during the mixing process and improve the Recycled Aggregate Concrete mix-design. The influence of some important materials and process parameters was evaluated: initial abrasion resistance and initial moisture of the Aggregates, mixer geometry, mixing time and mixing speed. To assess the mixing process effect on the Recycled Concrete Aggregate friability, three different aspects were evaluated; the mass loss (mass of fraction inferior to 2.5 mm) the grading and the angularity evolutions with mixing time of an initially 10-14 mm Aggregate. Tests were carried out in two types of laboratory Concrete mixers, a planetary 30 l mixer from Skako and an intensive 5 l Erich mixer. The results revealed that in normal laboratory setting of the mixers configuration, the mass loss for natural Aggregate (NA) is less than 1% of the coarse Aggregate. This percentage reach 3% for good quality Recycled Concrete Aggregate (MDE value of 21) and 5% for lower quality Recycled Concrete Aggregate (MDE value of 27). The mass loss directly depends on the mixing parameters and the degradation of the Recycled Concrete Aggregate drastically increased when the mixing speed was raised to 500 RPM. By analyzing the grading evolution during mixing, it was shown that both cleavage (creation of intermediate size particles) and attrition (creation of small particles) mechanisms influenced the Aggregate degradation. However, the configuration of mixing significantly influenced the proportion of attrition and cleavage mechanisms. To complete this work, the angularity evolution showed that Recycled Concrete Aggregate surface becomes smoother and the edges more rounded after mixing.

  • Recycled Concrete Aggregate attrition during mixing new Concrete
    Construction and Building Materials, 2016
    Co-Authors: Jaime Moreno Juez, Bogdan Cazacliu, Alexis Cothenet, Riccardo Artoni, Nicolas Roquet
    Abstract:

    In this work, the Recycled Concrete Aggregate (RCA) friability during mixing was studied in order to better understand the evolution of this material during the mixing process and improve the Recycled Aggregate Concrete mix-design. The influence of some important materials and process parameters was evaluated: initial abrasion resistance and initial moisture of the Aggregates, mixer geometry, mixing time and mixing speed. To assess the mixing process effect on the Recycled Concrete Aggregate friability, three different aspects were evaluated; the mass loss (mass of fraction inferior to 2.5 mm) the grading and the angularity evolutions with mixing time of an initially 10-14 mm Aggregate. Tests were carried out in two types of laboratory Concrete mixers, a planetary 30 l mixer from Skako and an intensive 5 l Erich mixer. The results revealed that in normal laboratory setting of the mixers configuration, the mass loss for natural Aggregate (NA) is less than 1% of the coarse Aggregate. This percentage reach 3% for good quality Recycled Concrete Aggregate (MDE value of 21) and 5% for lower quality Recycled Concrete Aggregate (MDE value of 27). The mass loss directly depends on the mixing parameters and the degradation of the Recycled Concrete Aggregate drastically increased when the mixing speed was raised to 500 RPM. By analyzing the grading evolution during mixing, it was shown that both cleavage (creation of intermediate size particles) and attrition (creation of small particles) mechanisms influenced the Aggregate degradation. However, the configuration of mixing significantly influenced the proportion of attrition and cleavage mechanisms. To complete this work, the angularity evolution showed that Recycled Concrete Aggregate surface becomes smoother and the edges more rounded after mixing.

Suksun Horpibulsuk - One of the best experts on this subject based on the ideXlab platform.

  • Cement stabilisation of Recycled Concrete Aggregate modified with polyvinyl alcohol
    International Journal of Pavement Engineering, 2020
    Co-Authors: Teerasak Yaowarat, Suksun Horpibulsuk, Arul Arulrajah, Farshid Maghool, Mehdi Mirzababaei, Ahmad Safuan A. Rashid, Avirut Chinkulkijniwat
    Abstract:

    During the past few decades, the engineering and geotechnical properties of Recycled Concrete Aggregate (RCA) has been investigated to evaluate its potential to use as a road construction material....

  • Recycled Concrete Aggregate municipal glass blends as a low carbon resource material for footpaths
    Road Materials and Pavement Design, 2018
    Co-Authors: Arul Arulrajah, Monzur Alam Imteaz, Yanjun Du, Suksun Horpibulsuk, Jack Shuilong Shen
    Abstract:

    Construction and Demolition (C&D) materials comprising Recycled Concrete Aggregate (RCA), fine Recycled glass (FRG) and a blend comprising 85% RCA with 15% FRG (85RCA/15FRG) were evaluated for thei...

  • Interface shear behaviours between Recycled Concrete Aggregate and geogrids for pavement applications
    International Journal of Pavement Engineering, 2018
    Co-Authors: Apichat Suddeepong, Suksun Horpibulsuk, Avirut Chinkulkijniwat, Narong Sari, Arul Arulrajah
    Abstract:

    The usage of Recycled Concrete Aggregate (RCA) in pavement applications is a sustainable approach for future infrastructure development, given the significant environmental benefits. Geogrid reinfo...

  • Recycled Concrete Aggregate/municipal glass blends as a low-carbon resource material for footpaths
    Road Materials and Pavement Design, 2016
    Co-Authors: Arul Arulrajah, Suksun Horpibulsuk, Monzur Alam Imteaz, Jack Shuilong Shen
    Abstract:

    Construction and Demolition (C&D) materials comprising Recycled Concrete Aggregate (RCA), fine Recycled glass (FRG) and a blend comprising 85% RCA with 15% FRG (85RCA/15FRG) were evaluated for thei...

  • modulus of rupture evaluation of cement stabilized Recycled glass Recycled Concrete Aggregate blends
    Construction and Building Materials, 2015
    Co-Authors: Arul Arulrajah, Mahdi M Disfani, Hamed Haghighi, Alireza Mohammadinia, Suksun Horpibulsuk
    Abstract:

    Abstract Construction and Demolition (C&D) wastes are increasingly used as construction material in a range of civil engineering applications. Fine Recycled Glass (FRG) is collected at municipal kerbsides and its usage to date has been limited to unbound pavement layers. This research was undertaken to evaluate the performance of FRG as a supplementary material in blends with cement stabilized Recycled Concrete Aggregate (RCA). Laboratory evaluation was undertaken on the RCA/FRG blends with 10%, 20% and 30% FRG content and stabilized with 3% medium setting General Blend (GB) cement. The laboratory evaluation was comprised of pH, plasticity index, foreign materials content, particle size distribution, linear shrinkage, California Bearing Ratio, modified Proctor compaction, Repeated Load Triaxial test, Unconfined Compressive Strength test and flexural beam tests. The cement stabilized RCA/FRG blends with up to 30% FRG content were found to have physical properties, which comply with the local state road authority requirements. The results of Repeated Load Triaxial tests indicated the RCA/FRG blends performed well with 30% FRG content just on the border line for bound pavement material. Unconfined Compression Strengths met the minimum requirement for 7 days of curing for all blends, while the 28 day strength of the blends showed a significant improvement with curing. The results of the flexural beam tests were noted to be consistent with past works with cement stabilized virgin quarry rock products. The modulus of rupture and flexural modulus for all the cement-stabilized RCA/FRG blends indicate that these blends are suitable for applications such as cement-stabilized pavement bases/subbases. The fatigue life was also within the range previously reported for quarry materials. The cement-stabilized blends with FRG as a supplementary material with up to 30% FRG content and 3% GB cement were found to have physical and strength properties, which would comply with road authority requirements.

Arul Arulrajah - One of the best experts on this subject based on the ideXlab platform.