Physical and Mechanical Properties of Treated Recycled Aggregate Concretes: Combination of Mechanical Treatment and Silica Fume

2021 ◽  
Vol 33 (6) ◽  
pp. 04021096
Author(s):  
Hasan Dilbas ◽  
Özgür Çakır
Keyword(s):  
Mechanical Properties ◽  
Silica Fume ◽  
Mechanical Treatment ◽  
Physical And Mechanical Properties ◽  
Recycled Aggregate

Study on Performance of Recycled Aggregate Concrete

2011 ◽  
Vol 477 ◽  
pp. 280-289 ◽  
Author(s):  
Shao Wei Yao ◽  
Zhen Guo Gao ◽  
Chang Rui Wang
Keyword(s):  
Mechanical Properties ◽  
Coarse Aggregate ◽  
Physical And Mechanical Properties ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Chemical Solution ◽  
Aggregate Concrete ◽  
Recycled Coarse Aggregate ◽  
Natural Aggregate ◽  
Strength And Durability

The properties of recycled coarse aggregate and the slump, the physical and mechanical properties and durability of recycled aggregate concrete were studied through tests. The results indicate that the slump, compressive strength and durability of concrete with recycled aggregate are lower than that of concrete with natural aggregate when recycled coarse aggregate fully absorbs water. However, the slump can be similar to that of concrete with natural aggregate. The properties of recycled aggregate concrete can be improved by strengthening the recycled coarse aggregate, and it is also found that the recycled coarse aggregate strengthened by grinding is superior to that soaked by chemical solution.

scholarly journals Recycled Mortars with Ceramic Aggregates. Pore Network Transmutation and Its Relationship with Physical and Mechanical Properties

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1543
Author(s):  
Francisca Guadalupe Cabrera-Covarrubias ◽  
José Manuel Gómez-Soberón ◽  
Carlos Antonio Rosas-Casarez ◽  
Jorge Luis Almaral-Sánchez ◽  
Jesús Manuel Bernal-Camacho
Keyword(s):  
Mechanical Properties ◽  
Image Analysis ◽  
Open Porosity ◽  
Gas Adsorption ◽  
Physical And Mechanical Properties ◽  
Recycled Aggregate ◽  
Bet Surface Area ◽  
Sem Image ◽  
The Relationship ◽  
Sem Image Analysis

The porosity of mortars with recycled ceramic aggregates (10, 20, 30, 50, and 100% as a replacement of natural aggregate) was evaluated and analyzed using three different techniques. The results of gas adsorption (N2), Scanning Electron Microscopy (SEM) image analysis and open porosity allowed establishing the relationship between the recycled aggregate content and the porosity of these mortars, as well as the relationship between porosity and the physical and mechanical properties of the mortars: absorption, density, compressive strength, modulus of elasticity, and drying shrinkage. Using the R2 coefficient and the equation typology as criteria, additional data such as Brunauer, Emmett, and Teller (BET) surface area (N2 adsorption) established significant correlations with the mentioned properties; with SEM image analysis, no explanatory relationships could be established; and with open porosity, revealing relationships were established (R2 > 0.9). With the three techniques, it was confirmed that the increase in porosity is related to the increase in the amount of ceramic aggregate; in particular with gas adsorption (N2) and open porosity. It was concluded that the open porosity technique can explain the behavior of these recycled mortars with more reliable data, in a simple and direct way, linked to its establishment with a more representative sample of the mortar matrix.

scholarly journals EFFECT OF THERMO-MECHANICAL TREATMENT ON PROPERTIES OF PARICA PLYWOODS (Schizolobium amazonicum Huber ex Ducke)

2017 ◽  
Vol 41 (1) ◽  
Author(s):  
Mírian de Almeida Costa ◽  
Cláudio Henrique Soares Del Menezzi
Keyword(s):  
Mechanical Properties ◽  
Mechanical Treatment ◽  
Physical And Mechanical Properties ◽  
The Other ◽  
Modulus Of Rupture ◽  
Thermal Treatments ◽  
Mechanical Compression ◽  
Specific Mass ◽  
Thermo Mechanical Treatment ◽  
Temperature And Pressure

ABSTRACT Thermo-mechanical treatment is a technique for wood modification in which samples are densified by means of heat and mechanical compression, applied perpendicularly to fibers, which under different combinations of time, temperature, and pressure increases wood density and thus improve some of its properties. This study aimed to treat thermo-mechanically parica plywood and observe the effects on its physical and mechanical properties. Specimens were submitted to two treatments, 120 and 150 ºC, remaining under pressure for seven minutes and, subsequently, under zero pressure for 15 minutes. Results showed a significant increase in specific mass from 0.48 g cm-3 to an average of 0.56 g cm-3, and a compression ratio of about 31.7% on average. Physical properties also varied significantly and results showed that treated samples swelled and absorbed more water than those untreated, leading to a greater thickness non-return rate. This indicates the proposed thermal treatments did not release the internal compressive stress generated during panel pressing, not improving its dimensional stability as a result. On the other hand, mechanical properties were positively affected, leading to an increase of 27.5% and 51.8% in modulus of rupture after treatments at 120 and 150 ºC, respectively. Modulus of elasticity and glue-line shear strength did not vary statistically and Janka hardness was 29.7% higher after treatment at 150 ºC.

The Behavior of FRA Concrete with High Replacement Ratio

2018 ◽  
Vol 760 ◽  
pp. 204-209 ◽  
Author(s):  
Magdaléna Šefflová
Keyword(s):  
Mechanical Properties ◽  
Physical And Mechanical Properties ◽  
Absorption Capacity ◽  
Recycled Aggregate ◽  
Partial Replacement ◽  
Hardened Concrete ◽  
Replacement Ratio ◽  
Natural Sand ◽  
Concrete Mixtures

This study deals with determination of the properties of the fine recycled aggregate (FRA) concrete with partial replacement of natural sand in concrete mixtures. The FRA was obtained from concrete waste and crushed on fraction 0 – 4 mm by laboratory jaw crusher. The geometrical and physical properties of natural sand and the FRA were tested. The main goal of this study is evaluation of the basic physical and mechanical properties of the concrete with partial natural sand replacement by the FRA such as workability, water absorption capacity, compressive strength and flexural strength. A total four concrete mixtures were prepared. The first concrete mixture was prepared only with natural sand, did not include the FRA. In other concrete mixtures, natural sand was replaced by the FRA in various replacement ratios (40 %, 50 %, and 60 %). All concrete mixtures were designated with the same parameters for clear comparison. The workability of fresh concrete mixtures and physical and mechanical properties of hardened concrete were tested.

Physical and mechanical characteristics of cement mortars and concretes with addition of clinoptilolite from Beli Plast deposit (Bulgaria), silica fume and fly ash

Clay Minerals ◽  
2011 ◽  
Vol 46 (2) ◽  
pp. 213-223 ◽  
Author(s):  
V. Lilkov ◽  
I. Rostovsky ◽  
O. Petrov
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Silica Fume ◽  
Mechanical Characteristics ◽  
Physical And Mechanical Properties ◽  
Specific Pore Volume ◽  
Cement Mortars ◽  
Physical And Mechanical Characteristics

AbstractCement mortars and concretes incorporating clinoptilolite, silica fume and fly ash were investigated for changes in their physical and mechanical properties. It was found that additions of 10% clinoptilolite and 10% Pozzolite (1:1 mixture of silica fume and fly ash) were optimal for improvement of the quality of the hardened products, giving 8% and 13% increases in flexural and compressive strength respectively. The specific pore volume of the mortars incorporating zeolite decreased between the 28th and 180th day to levels below the values for the control composition due to the fact that clinoptilolite exhibits its pozzolanic activity later in the hydration. In these later stages, pores with radii below 500 nm increased at the expense of larger pores. The change in the pore-size distribution between the first and sixth months of hydration occurs mostly in the mortars with added zeolite.

scholarly journals Effects of thermo-hydro-mechanical treatments on various physical and mechanical properties of poplar (Populus) wood

BioResources ◽  
2020 ◽  
Vol 15 (4) ◽  
pp. 9596-9610
Author(s):  
Yali Shao ◽  
Lili Li ◽  
Zhangjing Chen ◽  
Sunguo Wang ◽  
Ximing Wang
Keyword(s):  
Mechanical Properties ◽  
Thermal Treatment ◽  
Modulus Of Elasticity ◽  
Mechanical Treatment ◽  
Elasticity Modulus ◽  
Physical And Mechanical Properties ◽  
Modulus Of Rupture ◽  
Compression Rate ◽  
Thickness Swelling ◽  
Maximum Thickness

Poplar (Populus) wood was subjected in this work to thermo-hydro-mechanical treatment. The influence of the treatment parameters on the physical and mechanical properties were investigated. The wood samples were densified under three compression ratios (0%, 30%, and 50%), and thermally treated at three temperatures (180 °C, 200 °C, and 220 °C), at three thermal treatment durations (3 h, 4 h, and 5 h). The density, modulus of elasticity, modulus of rupture, radial hardness, and thickness swelling were measured. The results showed that the densities of the samples increased by 36.6% to 49.7%. As the compression rate increased, the temperature, duration, modulus of elasticity, modulus of rupture, and hardness increased. However, the dimensions of the densified samples were less stable. Compared to the densified samples, the maximum thickness swelling could be reduced by 74% (from 29.7% to 7.8%) when subjected to a thermal treatment at 220 °C for 3 h.

scholarly journals Strength Characteristic of Recycled Aggregate with Silica Fume As Admixture

2021 ◽  
Vol 10 (4) ◽  
pp. 243-246
Author(s):  
Rajashekar Yergol ◽  
Lingaraj Shastri
Keyword(s):  
Silica Fume ◽  
Physical And Mechanical Properties ◽  
Silica Content ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Target Strength ◽  
Test Results ◽  
Conventional Concrete ◽  
Unreacted Core ◽  
Micro Silica

In this study, conventional concrete is developed using recycled aggregates with micro silica (silica fume) as admixture. The concrete mix is designed for target strength of 25 MPa. Coarse aggregate were partially with recycled aggregate at 15 %, 30 % and 45 %. The relative parameters influencing the strength of concrete were studied in terms of recycled aggregate and silica content respectively. Test results reveled concrete produced with 45% of recycled aggregate tend to reduce the strength by 12% whereas addition of silica fume (10%) enhances the strength comparable to control mix (M25). Addition of microsilica functions as microfilling action in unreacted core of concrete which enhances the physical and mechanical properties of concrete. The significant reduction in compressive strength is noticed, when the recycled aggregate is increased beyond 30%

scholarly journals ANÁLISE DAS PROPRIEDADES FÍSICAS E MECÂNICAS DO CONCRETO PRODUZIDO COM RESÍDUO SÓLIDO DE CERÂMICA VERMELHA

2012 ◽  
Vol 04 (02) ◽  
pp. 01-11 ◽  
Author(s):  
Cassio Fabian S. Campos ◽  
Giovane Bozette Mazini ◽  
Guilherme A. da Silva Neto
Keyword(s):  
Mechanical Properties ◽  
Construction Industry ◽  
Physical And Mechanical Properties ◽  
Specific Weight ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Mechanical Compression ◽  
Conventional Concrete ◽  
The Difference ◽  
Physical Changes

The construction industry accounts for the largest share of consumption of natural resources among all other areas, about 50%. Consequently is also the largest generator of waste. One of these tailings is red ceramic, which due to its fragility break easily generate large amount of debris. This project aimed to examine the possibility of reuse of waste as aggregate for concrete comparing their physical and mechanical properties, with conventional concrete. We compared the behaviors of different traits in concrete with a gradual replacement of 20% of natural coarse aggregate by recycled aggregate red ceramic to achieve 100% recycled aggregate, evaluating possible changes in density, absorption and voids, as well as the mechanical compression. The reference concrete results presented in the order of 25 MPa at 28 days of age, since the concrete produced with recycled aggregates showed lower results of the compressive strength of up to30%. The other indices also suffered physical changes as the slump that had values 4 times higher, the level of absorption and voids which increased 2-3 three times in concrete with recycled aggregate. This happens due to the difference between the densities of crushed stone and ceramics. Although the ceramic adversely affect the mechanical properties, this difference becomes lighter concrete, or decreases its specific weight, which may be favorable in some situations.

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