A Study on the Use of Construction Wastes as Coarse Aggregates on High Performance Concrete

2010 ◽  
Vol 163-167 ◽  
pp. 1525-1531
Author(s):  
Chung Ming Ho ◽  
Wei Tsung Tsai
Keyword(s):  
Compressive Strength ◽  
High Performance ◽  
High Performance Concrete ◽  
Recycled Concrete ◽  
Recycled Aggregates ◽  
Mechanical And Thermal Properties ◽  
Loss On Ignition ◽  
Coarse Aggregates ◽  
Flow Test ◽  
Water To Cement Ratio

In recent years, because of rising consciousness on environmental protection and the lacking of construction waste dumping yards, recycling of construction wastes has been promoted extensively. The purpose of this study is to ascertain the effect on properties of the fresh and harden concrete replacing coarse aggregates by construction wastes under ambient and enhanced temperatures exposure. This research mainly concentrates on high performance recycled concrete (HPRC); by adding different amount of superplasticizer into the HPRC and to test and compare its mechanical and thermal properties with general high performance concrete (HPC). Thereafter, tests are carried out determine its compressive strength, residual strength after high temperature and the loss on ignition of the HPRC mixed with two water-to-cement ratios and different replacement proportions of recycled aggregates. Similar tests, such as the slump test and slump flow test, are carried out both on the HPRC and HPC. When the water-to-cement ratio is 0.3 and the amount of superplasticizer added is 1.2%, HPRC has the best performance. The specimens with 100% recycled aggregates were 31% below the control concrete sample in compressive strength at age of 28 days. By the way of adding admixture, the recycled concrete could reach the demand strength of the HPC. The results show that it is feasible to allow a higher replacement percentage of construction wastes for producing concrete products.

scholarly journals Sulfate Resistance of Recycled Aggregate Concrete with GGBS and Fly Ash-Based Geopolymer

Materials ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1247 ◽  
Author(s):  
Jianhe Xie ◽  
Jianbai Zhao ◽  
Junjie Wang ◽  
Chonghao Wang ◽  
Peiyan Huang ◽  
...  
Keyword(s):  
Fly Ash ◽  
Construction Projects ◽  
High Performance ◽  
High Performance Concrete ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Aggregate Concrete ◽  
Sulfate Resistance ◽  
Coarse Aggregates

There is a constant drive for the development of ultra-high-performance concrete using modern green engineering technologies. These concretes have to exhibit enhanced durability and incorporate energy-saving and environment-friendly functions. The object of this work was to develop a green concrete with an improved sulfate resistance. In this new type of concrete, recycled aggregates from construction and demolition (C&D) waste were used as coarse aggregates, and granulated blast furnace slag (GGBS) and fly ash-based geopolymer were used to totally replace the cement in concrete. This study focused on the sulfate resistance of this geopolymer recycled aggregate concrete (GRAC). A series of measurements including compression, X-ray diffraction (XRD), and scanning electron microscopy (SEM) tests were conducted to investigate the physical properties and hydration mechanisms of the GRAC after different exposure cycles in a sulfate environment. The results indicate that the GRAC with a higher content of GGBS had a lower mass loss and a higher residual compressive strength after the sulfate exposure. The proposed GRACs, showing an excellent sulfate resistance, can be used in construction projects in sulfate environments and hence can reduce the need for cement as well as the disposal of C&D wastes.

Microstructural Features of Recycled Aggregate Concrete: From Non-Structural to High-Performance Concrete

2019 ◽  
Vol 25 (3) ◽  
pp. 601-616 ◽  
Author(s):  
Diogo Pedro ◽  
Mafalda Guedes ◽  
Jorge de Brito ◽  
Luís Evangelista
Keyword(s):  
High Performance ◽  
Mechanical Performance ◽  
High Performance Concrete ◽  
Concrete Strength ◽  
High Strength ◽  
Recycled Concrete ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Sequential Approach

AbstractThe use of concrete-recycled aggregates to produce high-performance concrete is limited by insufficient correlation between resulting microstructure and its influence on mechanical performance reproducibility. This work addresses this issue in a sequential approach: concrete microstructure was systematically analyzed and characterized by scanning electron microscopy and results were correlated with concrete compressive strength and water absorption ability. The influence of replacing natural aggregates (NA) with recycled concrete aggregates (RCA), with different source concrete strength levels, of silica fume (SF) addition and of mixing procedure was tested. The results show that the developed microstructure depends on the concrete composition and is conditioned by the distinct nature of NA, recycled aggregates from high-strength source concrete, and recycled aggregates from low-strength source concrete. SF was only effective at concrete densification when a two-stage mixing approach was used. The highest achieved strength in concrete with 100% incorporation of RCA was 97.3 MPa, comparable to that of conventional high-strength concrete with NA. This shows that incorporation of significant amounts of RCA replacing NA in concrete is not only a realistic approach to current environmental goals, but also a viable route for the production of high-performance concrete.

Experimental Study on Basic Properties of Fair-Faced Concrete for Urban Bridge

2013 ◽  
Vol 438-439 ◽  
pp. 1156-1159 ◽  
Author(s):  
Li Hui Jin ◽  
Xiao Lu Ma ◽  
Xiao Ke Li
Keyword(s):  
Compressive Strength ◽  
High Performance ◽  
Surface Brightness ◽  
High Performance Concrete ◽  
Hardened Concrete ◽  
Basic Properties ◽  
Mix Proportion ◽  
Water To Cement Ratio ◽  
Color Uniformity

As the high-performance concrete with remarkable characteristics of artistic presentation and ecological sense, fair-faced concrete is becoming more and more attention by the department of urban construction. As part of the research project, this paper gives the supplement study of the mix proportion and basic properties of C50 fair-faced concrete, and summarizes the experimental results of the apparent quality of C30 and C50 fair-faced concrete affected by the mold releases. Considering the parameters of water to cement ratio, cement dosage, percent of pulverized fly ash, sand ratio, water reducer and mold releases, the workability of fresh concrete and the compressive strength of hardened concrete at 7 days, 28 days and 56 days, as well as the apparent quality and surface brightness were measured, the mix proportions of C30 and C50 fair-faced concretes for construction of urban bridge were determined. Based on the measurements of surface brightness, color uniformity, resistance to water penetration, stain resistance and compressive strength of fair-faced concrete, the formwork lacker can be firstly selected as the mold release, and the mix oil (diesel: machine oil=3:7) can be the alternative selection.

The Effect of Different Sand Gradation with Ultra High Performance Concrete (UHPC)

2018 ◽  
Vol 280 ◽  
pp. 476-480 ◽  
Author(s):  
N.A. Hamiruddin ◽  
R. Abd Razak ◽  
K. Muhamad ◽  
M.Z.A. Mohd Zahid ◽  
C.N.S. Che Ab Aziz
Keyword(s):  
Compressive Strength ◽  
High Performance ◽  
High Performance Concrete ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Material Research ◽  
Ultra High Performance Concrete ◽  
New Class ◽  
Flow Test

Advances in concrete material research has introduced to development the new class of concrete which is known as Ultra High Performance Concrete (UHPC). Due to the most exceedingly awful on nature coarse aggregate quality, UHPC was delivered to success in concrete. This study investigated the effect of differentsand gradation (63-300μm, 300-600μm, 600-1180μm, and normal sand) on compressive strength and ultrasonic pulse velocity (UPV) of UHPC. The rheology of UHPC mixtures was determined by flow test conducted according to ASTM C1611 and the compression testwas performed to measure concrete compression strength at 7 and 28 days according to BS 1881-116 (1983). To determine the quality of concrete, UPV test were conducted according to BS 1881 part 201 (1986).From the experimental results, the results indicated that sand grading with 600-1180μm obtained the highest in compressive strength and UPV.The compressive strength at 28 days achieved 100 MPawith direct transmission of UPV 4.5% higher than semi direct.

scholarly journals Optimization of High-Performance-Concrete properties containing fine recycled aggregates using mixture design modeling

2021 ◽  
Vol 15 (57) ◽  
pp. 50-62
Author(s):  
Tounsia Boudina ◽  
Dalila Benamara ◽  
Rebih Zaitri
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Pozzolanic Reaction ◽  
Recycled Concrete ◽  
Recycled Aggregates ◽  
Cement Matrix ◽  
Hardened Concrete ◽  
Natural Sand ◽  
Fine Aggregates ◽  
Result Show

This investigation means to predict and modeling the fresh and hardened concrete behavior containing fine aggregates from concrete and brick wastes, for different recycled aggregates substitution rates. To succeed this, the design of experiments DOE method was used. It is observed that slump of recycled concrete is significantly influenced by the content in recycled concrete aggregates (RCA), natural sand (NS) and recycled brick aggregates (RBA), respectively.The compressive strength (CS) reaches a maximum value of 83.48 MPa with factors values of 25% RBA, and 75% RCA. And HPC’s based on RBA sand presented greater values of flexural strength at 7 days than HPC’s based on RCA sand, it was revealed that this is due to the RBA fines pozzolanic reaction and the production of new CSHs, which leads to better cement matrix densification.Under optimal conditions, themaximum desirability is 0.65, who has given HPC no added natural sand, by mixing recycled sands RBA (9.5%) with RCA (90.5%).The statistical terms result show that the expected models are very well correlated with the experimental data and have shown good accuracy.

scholarly journals Experimental Inspection on Shear Capacity in RCC Beams with Partial Replacement of Recycled Coarse Aggregates

2020 ◽  
Vol 9 (2) ◽  
pp. 321-326
Keyword(s):  
Compressive Strength ◽  
Load Ratio ◽  
Shear Capacity ◽  
Recycled Concrete ◽  
Recycled Aggregates ◽  
Partial Replacement ◽  
Age Group ◽  
Shear Span ◽  
Coarse Aggregates ◽  
The Relationship

Demolition waste increasing day by day. The old damaged building materials can be used in present buildings or other construction works. Especially the recycled aggregates are useful to the concrete structures. The experimental studies on the use of recycled coarse aggregate has been going on for many countries. This publication focuses on the relationship between the shear capacity and the flexural cracking load of reinforced recycled concrete beams with stirrups, this experimental Inspection with partial replacement of natural coarse aggregates (NAC) with recycled coarse aggregates (RAC) at different ages as 10, 20 and 30 years in various proportions as 20 per cent, 30 per cent, 40 per cent. For this, M30 grade of concrete is consider. Curing of specimens were done for 7 day and 28 days to conclude the maximum strengths. The obtained results of concrete with partial replacement of recycled aggregates of 10,20and 30 years age group conclude maximum compressive strength of 35.84 N/mm2 at 40% replacement of NCA with RCA of age group (10 years) and 34.12 N/mm2 at 30% replacement of NCA whit RCA of (20 years) age group and 36.14 N/mm2 20% replacement of NCA with RCA of age group (30 years). After the compressive strength, beam specimens were casted for 7day and 28 days. Based on test results of 8 beams, the relationship between the cracking load that causes a beam to crack in the middle of the shear span and the beam's shear capacity is confident. All beams are reinforced in the longitudinal direction only and only tested under two-point loading conditions. The average analytical cracking load ratio is 0.60.the mid-shear span at cracking load (Vcr-a/2) in comparison with the observed shear capacity (Vexp). The analytical cracking load ratio. The analytical cracking’s load was used in this exploration as it is more reliable than the observed cracking load. At mid-span, the shear capacity of most of the beams was shown to be 50%. The average shear capacity ratio to the related test crack load in the center of the shear span 0.43. The analysis showed that cracking loads are strongly related to the shear capacity of the members. This relationship can be used to develop recycled reinforced beam members ' shear design process.

scholarly journals Influence of Recycled High-Performance Aggregate on Deformation and Load-Carrying Capacity of Reinforced Concrete Beams

Materials ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 186 ◽  
Author(s):  
Barbara Sadowska-Buraczewska ◽  
Danuta Barnat-Hunek ◽  
Małgorzata Szafraniec
Keyword(s):  
Carrying Capacity ◽  
High Performance ◽  
High Performance Concrete ◽  
Concrete Beams ◽  
Recycled Concrete ◽  
Reinforced Concrete Beams ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Load Carrying Capacity ◽  
Load Carrying

The use of recycled concrete aggregates (RCA) in high performance concrete (HPC) was analyzed. The paper presents the experimental studies of model reinforced concrete beams with a rectangular section using high-performance recycled aggregates. Two variable contents of recycled aggregate concrete were used in this study: 50% and 100%. The experimental analyses conducted as immediate studies concerned the following issues: short time loads-deflection, load-carrying capacity of beams, deformation of concrete, cracks, and long-term loads-deflection. The comparative analysis involves the behavior of beams made of high performance concrete-high strength concrete (HPC-HSC) recycled aggregates with model control elements made of regular concrete based on natural aggregates. The deflection values for the recycled aggregate beams were 20% higher than in the case of the control beams made of HPC-HSC exclusively. Replacement of aggregate with recycled concrete aggregate resulted in a large decrease in the value of these two parameters, i.e., compression strength by about 42% and modulus of elasticity by about 33%.

Preparation and Properties of High-Performance Concrete with Ceramic Coarse Aggregate

2016 ◽  
Vol 852 ◽  
pp. 1413-1420
Author(s):  
Ben Ying Wu ◽  
Xi Wu Zhou ◽  
Jin Zhong Lu
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Silica Fume ◽  
High Performance ◽  
Coarse Aggregate ◽  
High Performance Concrete ◽  
Splitting Tensile Strength ◽  
Water Penetration ◽  
Concrete Material ◽  
Coarse Aggregates

High-performance concrete was prepared by using ceramic waste as coarse aggregate. The influences of several factors, such as the contents of ceramic coarse aggregates, fly ashes and silica fumes, on the properties of concrete material were investigated. The results show that the compressive strength of semi-porcelain coarse aggregate concrete are slightly lower than that of natural concrete, and the splitting tensile strength and the ratio of compressive strength and splitting tensile strength is similar to the ones of natural concrete. After fly ash and silica fume mixed, the compressive strength, the splitting tensile strength and the resistance to water penetration of concrete with semi-porcelain coarse aggregate increase significantly with the increase of silica fume content which meet the requirements of high-performance concrete. Concrete with orcelain coarse aggregate is only suitable for low strength concrete.

scholarly journals Strength properties of high-performance concretes with carbonate coarse aggregate

2011 ◽  
Vol 9 (2) ◽  
pp. 069-076
Author(s):  
Jacek Góra
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
High Performance ◽  
Coarse Aggregate ◽  
High Performance Concrete ◽  
Concrete Strength ◽  
Strength Properties ◽  
Splitting Tensile Strength ◽  
Coarse Aggregates

High performance concretes were tested to find an effect of the three different coarse aggregates (basalt, granite and dolomite) on concrete strength properties. All the results were analyzed statistically. Splitting tensile strength of high performance concrete with dolomite aggregate was significantly higher than that of concretes with basalt and granite aggregate. The effect of dolomite aggregate on compressive strength of HPC was much more advantageous than that of granite aggregate.

scholarly journals Experimental Study on Recycled Concrete Aggregates with Rice Husk Ash as Partial Cement Replacement

2018 ◽  
Vol 4 (10) ◽  
pp. 2305 ◽  
Author(s):  
Naraindas Bheel ◽  
Shanker Lal Meghwar ◽  
Samiullah Sohu ◽  
Ali Raza Khoso ◽  
Ashok Kumar ◽  
...  
Keyword(s):  
Experimental Study ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Rice Husk ◽  
Rice Husk Ash ◽  
Splitting Tensile Strength ◽  
Recycled Concrete ◽  
Recycled Aggregates ◽  
Concrete Aggregates ◽  
Coarse Aggregates

Concrete is highly utilized construction material around the globe and responsible for high depreciation of the raw materials. Consumption of this material in construction industry is arching upward day by day. On the other hand, debris of demolished concrete structures are being dumped as waste. For developing countries such waste is not a good sign and need its proper utilization by recycling it into useful product. In this consequence, this study is an attempt to utilize demolished waste concrete by converting into coarse aggregates. This research was conducted on recycled cement concrete aggregates of demolished structures and Rice Husk Ash (RHA). The purpose of this experimental study is to analyze the mechanical properties of concrete; when cement is partially replaced with RHA and natural aggregates by recycled aggregates (RA). In this study, the cement was replaced by RHA up to 10% by weight of cement. For experimental purpose, total 135 concrete specimens were prepared, cured and tested in Universal Testing Machine (UTM). Finally, laboratory results were compared in terms of compressive and splitting tensile strength made with normal and recycled coarse aggregates. All the specimens were prepared at 1:1.5:3 with 0.50 w/c ratio and tested at 7, 14, 21, 28 and 56 days curing ages. It is observed from experimental analysis that the workability of fresh normal concrete is 7% and 10% greater than recycled aggregates concrete blended with 10% RHA and only recycled aggregates concrete without RHA respectively. The compressive strength increases up to 6%, whilst splitting tensile strength increases 4% at 56 days curing, when the cement is replaced 10% by RHA. It is, further, concluded that with more than 10% RHA replacement with cement, the compressive strength decreases. This study would help the construction experts to use such wasted concrete into useable production of new concrete projects.

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