scholarly journals Preliminary Analysis of the Use of Construction Waste to Replace Conventional Aggregates in Concrete

Buildings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 81
Author(s):  
Fernando A. N. Silva ◽  
João M. P. Q. Delgado ◽  
António C. Azevedo ◽  
António G. B. Lima ◽  
Castorina S. Vieira
Keyword(s):  
Compressive Strength ◽  
Coarse Aggregate ◽  
Recycled Aggregate Concrete ◽  
Construction And Demolition Waste ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Fine Aggregate ◽  
Demolition Waste ◽  
Fine Aggregates ◽  
Mechanical Strengths

This work aims to study the influence of using construction and demolition waste in the replacement of coarse and fine aggregate to produce recycled aggregate concrete (RAC). A moderate compressive strength concrete made with usual fine and coarse aggregate was used as a benchmark material. Compressive and split tensile tests were performed using 120 cylindrical concrete specimens with 150 mm diameter and 300 mm length. Four-point flexural tests in reinforced beams made with conventional concrete and RAC were performed. The results obtained showed that the use of recycled fine aggregates, in both percentages of substitution investigated—50% and 100%— did not generate any deleterious influence on the values of compressive strength and split tensile strength of the RACs produced. Tin fact, the mechanical strengths of RACs produced with recycled fine aggregate were equal or higher than those from the reference concrete. The same behavior was not observed, however, when the recycled coarse aggregate was used. For this case, decreases in concrete mechanical strengths were observed, especially in compressive strength, with values around 35% lower when compared to the reference concrete. Tensile mechanical tests results confirmed the excellent behavior of all RACs made with replacement of usual fine aggregates by recycled. Bending tests performed in reinforced RAC beams had as objective to evaluate the deformation profile of the beams. The obtained results showed that RAC beams with full replacement of usual fine aggregate by the recycled aggregates have presented little changes in the global behavior, an aspect that encourages its use.

On Properties of Recycled Coarse Aggregate from Repeatedly Recycling Waste Concrete

2011 ◽  
Vol 368-373 ◽  
pp. 2185-2188
Author(s):  
Ping Hua Zhu ◽  
Xin Jie Wang ◽  
Jin Cai Feng
Keyword(s):  
Compressive Strength ◽  
Coarse Aggregate ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Fine Aggregate ◽  
Recycled Coarse Aggregate ◽  
Coarse Aggregates ◽  
Recycled Fine Aggregate ◽  
Waste Concrete

The properties of recycled coarsee aggregates from repeatedly recycling waste concrete were determined. In this study, five series of concrete mixtures using coarse and fine natural aggregates were prepared, which have the same objective slump value from 35mm to 50mm and different compressive strengths ranging from 25MPa to 60 MPa. These five concretes were crushed, sieved, washed with water, hot treatmented at 300°C before they were used as recycled aggregates. After that, recycled aggregate concrete (RAC) was produced with an objectively compressive strength of 30MPa, in which the recycled coarse aggregate was used as 30%, 70% and 90% replacements of natural coarse aggregate and recycled fine aggregate as 10%, 20%, and 30% replacements of natural fine aggregate. After that, these recycled concretes were used as second recycled aggregates to produce RAC with the same objectively compressive strength of 30MPa. The physical properties of coarse aggregates including apparent density, water absorption, attached mortar content and crushing value were tested and their mineral characteristics were analyzed. The results showed that the quality of recycled coarse aggregates from twicely recycling waste concrete reached the requirements from structural concrete.

scholarly journals Mechanical Strength Study on C&D Aggregates Replaced Concrete

2021 ◽  
Keyword(s):  
Compressive Strength ◽  
Recycled Concrete ◽  
Recycled Aggregate Concrete ◽  
Construction And Demolition Waste ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Steam Curing ◽  
Demolition Waste ◽  
Large Size ◽  
New Treatments

Abstract. Recycled concrete was produced to overcome the problem of disposal of construction and demolition waste and lack of availability of natural materials. To improve the characteristics of recycled concrete, new treatments and suggestions were given by the researchers. This paper investigates the compressive strength of recycled aggregate concrete having the replacement of 0, 30, 40, 50 & 60% recycled coarse aggregates. The compressive strength of recycled concrete in water curing is compared with steam curing. The compressive strength of concrete is not much affected because of the use of large size recycled aggregates. The use of saturated dried surface large size recycled aggregates improves the strength of concrete.

Applicability of recycled aggregates in concrete piles for soft soil improvement

2016 ◽  
Vol 35 (1) ◽  
pp. 56-64 ◽  
Author(s):  
Ronaldo A Medeiros-Junior ◽  
Carlos ET Balestra ◽  
Maryangela G Lima
Keyword(s):  
Compressive Strength ◽  
Bearing Capacity ◽  
Soft Soil ◽  
Construction And Demolition Waste ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Fine Aggregate ◽  
Demolition Waste ◽  
Soft Soils ◽  
Natural Aggregates

The expressive generation of construction and demolition waste is stimulating several studies for reusing this material. The improvement of soft soils by concrete compaction piles has been widely applied for 40 years in some Brazilian cities. This technique is used to improve the bearing capacity of soft soils, allowing executing shallow foundations instead of deep foundations. The compaction piles use a high volume of material. This article explored the possibility of using recycled aggregates from construction waste to replace the natural aggregates in order to improve the bearing capacity of the soft soil, regarding its compressive strength. Construction wastes from different stages of a construction were used in order to make samples of concrete with recycled aggregates. The strength of concretes with natural aggregates was compared with the strength of concretes with recycled (fine and coarse) aggregates. Results show that all samples met the minimum compressive strength specified for compaction piles used to improve the bearing capacity of soft soils. The concrete with recycled aggregate from the structural stage had even higher resistances than the concrete with natural aggregates. This behaviour was attributed to the large amount of cementitious materials in the composition of this type of concrete. It was also observed that concrete with recycled fine aggregate has a superior resistance to concrete with recycled coarse aggregate.

scholarly journals Effects of Recycled Aggregate Resin (RAR) in Concrete Material

2020 ◽  
Vol 11 (2) ◽  
Author(s):  
Sharifah Salwa Mohd Zuki ◽  
◽  
Shahiron Shahidan ◽  
Shivaraj Subramaniam ◽  
◽  
...  
Keyword(s):  
Epoxy Resin ◽  
Recycled Aggregate Concrete ◽  
Construction And Demolition Waste ◽  
Recycled Aggregate ◽  
Engineering Properties ◽  
Recycled Aggregates ◽  
Hardened Concrete ◽  
Demolition Waste ◽  
Split Tensile Strength ◽  
Close Proximity

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.

The Properties of Fine Recycled Aggregate Concrete Containing Recycled Bricks from Construction and Demolition Waste

2018 ◽  
Vol 760 ◽  
pp. 193-198 ◽  
Author(s):  
Kristina Fořtová ◽  
Tereza Pavlů
Keyword(s):  
Recycled Aggregate Concrete ◽  
Construction And Demolition Waste ◽  
Recycled Aggregate ◽  
Partial Replacement ◽  
Fine Aggregate ◽  
Demolition Waste ◽  
Natural Sand ◽  
Aggregate Concrete ◽  
Freeze Thaw ◽  
Recycled Fine Aggregate

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.

Influence of Recycled Aggregate on the Rheological Behavior of Cement Mortar

2014 ◽  
Vol 600 ◽  
pp. 297-307 ◽  
Author(s):  
Paulo Roberto Lopes Lima ◽  
Romildo Dias Toledo Filho ◽  
Otávio da Fonseca Martins Gomes
Keyword(s):  
Yield Stress ◽  
Plastic Viscosity ◽  
Construction And Demolition Waste ◽  
Recycled Aggregate ◽  
Fine Aggregate ◽  
Demolition Waste ◽  
Cement Ratio ◽  
Recycled Fine Aggregate ◽  
Fine Aggregates ◽  
Physical Tests

In this work it was studied the influence of recycled fine aggregate obtained from construction and demolition waste (CDW) on the rheological properties of Portland cement mortars. The CDW was initially separate in their main constituents (mortar, ceramic and concrete debris) at the laboratory and then grinded separately to the sand size in order to generate more homogeneous fine aggregates. The characterization of the natural and recycled sands was carried out through physical tests, X-ray diffraction, scanning electron microscopy (SEM), and image analysis (shape and texture description parameters). A conventional mortar and three mortars containing recycled sands were produced with a sand/cement ratio of 4 and consistency index of 255±5 mm. The consistency was kept constant by ranging the water-cement ratio from 0.58 to 1.14. The rheological study was performed using a rotating viscometer to obtain torque-rotation ratio and to calculate the yield stress and plastic viscosity. The results indicate that the presence of recycled aggregate causes a lowering of both yield stress and plastic viscosity with respect to the mortar containing natural aggregate.

scholarly journals Evaluation of the physical-mechanical properties of cement-lime based masonry mortars produced with mixed recycled aggregates

2020 ◽  
Vol 70 (337) ◽  
pp. 210 ◽  
Author(s):  
R. L.S. Ferreira ◽  
M. A.S. Anjos ◽  
E. F. Ledesma ◽  
J. E.S. Pereira ◽  
A. K.C. Nóbrega
Keyword(s):  
Mechanical Properties ◽  
Construction And Demolition Waste ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Demolition Waste ◽  
Long Run ◽  
Lime Mortars ◽  
Binder Ratio ◽  
Mechanical Strengths ◽  
One Way Anova

This study investigated the physical-mechanical effects of cement-lime mortars containing recycled aggregate of construction and demolition waste (CDW). The natural aggregate (NA) was replaced by volume at 25%, 50%, 75% and 100% by mixed recycled aggregate (MRA) obtained from the CDW crushing. Five types of mortars were prepared with a volumetric ratio of 1:1:6 (cement, lime and aggregate) and water/binder ratio based on the fixed consistency of 260 mm. The effects of MRA on fresh and hardened mortars’ properties were analyzed. The results were analyzed using a one-way ANOVA. MRA incorporation improved most of the physical-mechanical properties of mortars tested, except for hardened bulk density, water absorption and porosity. In the long-run, mechanical strengths significantly increased in all compositions, especially those with higher percentages of MRA. The results obtained showed that the use of MRA in masonry mortars is an alternative to reduce the generation of waste and consumption of natural resources.

Research on Strength Properties of Concrete Using Aggregates from Repeatedly Recycling Concrete Waste

2014 ◽  
Vol 665 ◽  
pp. 147-150 ◽  
Author(s):  
Ping Hua Zhu ◽  
Yi Lei
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Coarse Aggregate ◽  
Strength Properties ◽  
Splitting Tensile Strength ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Fine Aggregate ◽  
Replacement Ratio ◽  
Design Strength

The strength properties of recycled aggregate concrete (RAC) using aggregates from repeatedly recycling concrete waste were studied. The relationships between cube compressive strength and splitting tensile strength and between each strength and replacement ratio of recycled aggregate to natural aggregate were established. The results showed that the strength properties of RAC with the design strength of 30MPa can be satisfied when the quality of recycled coarse and fine aggregates met respectively the needs of Grade II in GB/T25177-2010 and Grade III in GB/T25176-2010, with the replacement ratio to natural coarse aggregate and natural fine aggregate no more than 70% and 50%. Both strengths decreased and then increased for a while before descending again with increasing replacement ratio of recycled coarse aggregate, and decreased continuously with the increase of replacement ratio of recycled fine aggregate. The relationship between cube compressive strength and splitting tensile strength of RAC was found to be exponential function.

scholarly journals Development of Concrete Incorporating Recycled Aggregates, Hydrated Lime and Natural Volcanic Pozzolan

2021 ◽  
Vol 6 (11) ◽  
pp. 155
Author(s):  
Natividad Garcia-Troncoso ◽  
Bowen Xu ◽  
Wilhenn Probst-Pesantez
Keyword(s):  
Compressive Strength ◽  
Recycled Concrete ◽  
Construction And Demolition Waste ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Partial Replacement ◽  
Demolition Waste ◽  
Crushed Concrete ◽  
Natural Pozzolana ◽  
Concrete Materials

Recycling of construction and demolition waste is a central point of discussion throughout the world. The application of recycled concrete as partial replacement of mineral aggregates in concrete mixes is one of the alternatives in the reduction of pollution and savings in carbon emissions. The combined influence of the recycled crushed concrete, lime, and natural pozzolana on the mechanical and sustainable properties of concrete materials is firstly proposed in this study. In this research, unconventional construction materials are employed to produce concrete: the recycled crushed concrete is used as coarse aggregate, while lime and natural pozzolana are used as a partial replacement for cement. Substitutions of 10%, 20%, 50% of gravel are made with recycled aggregates, and 2%, 5%, 10% of cement with lime and natural pozzolan. Tests on the fresh and hardened properties, destructive (compressive strength) and non-destructive tests (sclerometer rebound and ultrasound) of mixtures are carried out. It is shown that the use of recycled materials can provide an increase in compressive strength of up to 34% with respect to conventional concrete. Life cycle cost and sustainability assessments indicate that concrete materials incorporating recycled aggregate possess good economic and environmental impacts.

scholarly journals Flexural Behaviour of RC Beams with Recycled Aggregates

2019 ◽  
Vol 8 (6S3) ◽  
pp. 1522-1525
Keyword(s):  
Coarse Aggregate ◽  
Raw Material ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Project Work ◽  
Fine Aggregate ◽  
Fine Aggregates ◽  
Glass Aggregate ◽  
Efficient Alternative ◽  
Cost Efficient

-Continuous raw material demand was increased in concrete productions which requires good quality and cost efficient alternative materials like Recycled Coarse Aggregate, M Sand and Glass as aggregate. This paper reports the behaviour of concrete using Glass aggregate as Fine Aggregate and Recycled aggregate as Coarse Aggregate replacement in concrete up to 15% and 30% respectively. In this project work, the concrete grade M25 was selected and IS method was used for mix design. The properties of Cement, M-Sand, Natural Coarse Aggregate, Glass asAggregate and Recycled Aggregate were investigated. The Beam Specimens were casted with and without C&D waste (Coarse Aggregate Replaced with Recycled Aggregate at 30% and Fine Aggregates replaced with Glass Aggregate at 15%). Vibration Analysis were made by using FFT analyser to determine acceleration characteristics. The work is focused on possible conservation of natural resources by substituting with waste material by suggesting a possible reuse option for Construction waste.

Sign in / Sign up

Export Citation Format

Share Document