Influence of Morphology of Cathode-Ray Tube Glass as Coarse Aggregates on Compressive Strength and Water Absorption of Concrete

The study on the substitution for natural coarse aggregates using waste CRT funnel glass in spherically shapes is still limited. In this paper, the waste CRT glass has been processed to form a spherical CRT glass (GS) and crushed CRT glass (GC), which were used as a coarse aggregate in concrete production. Results indicated that the inclusion of GS and GC has lower the compressive strength and decreased the rate of capillary water absorption of concrete. It was demonstrated that the morphology properties of GS and GC (shape, surface texture, size, grading) is significantly affected the concrete properties.

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The Influence of Discharge Time, Kind of Additive, and Kind of Aggregate on the Properties of Three-Stage Mixed Concrete

Sustainability ◽

10.3390/su10113862 ◽

2018 ◽

Vol 10 (11) ◽

pp. 3862 ◽

Cited By ~ 2

Author(s):

Alena Sicakova ◽

Karol Urban

Keyword(s):

Compressive Strength ◽

Water Absorption ◽

Recycled Concrete ◽

Recycled Aggregates ◽

Concrete Aggregate ◽

Discharge Time ◽

Concrete Mixtures ◽

Concrete Properties ◽

Concrete Production ◽

The Impact

Application of recycled aggregates (RA) for concrete production is limited due to their poor quality. While the environmental benefits of using the RA are well accepted, some unsolved problems prevent this type of material from wide application in structural concrete. The research and development of techniques which can minimize the adverse effect of RA on the concrete properties are highly requested. A specific mixing approach can also be helpful; here, mineral additives play a significant role for improvement of RA performance within the mixing process. However, delivery process can influence the homogeneity and uniformity of the concrete mixtures, resulting in negative effect on technical parameters. In this study, the impact of delivery time (0 min, 45 min, and 90 min) on the set of hardened concrete properties is presented while the three-stage mixing is used. Two kinds of additives—fly ash (FA) and recycled concrete powder (RCP)—were tested to coat the coarse fraction of recycled concrete aggregate (RCA) in the first step of mixing. For comparison, cement as coating material and natural aggregate instead the RCA were also used. The following parameters were tested after 28 days of setting and hardening: density, compressive strength, splitting tensile strength, water absorption capacity, and depth of penetration of water under pressure. Generally, 90 min of working with concrete mixtures left no significantly negative influence on tested characteristics. Based on ANOVA results, with prolonged discharge time, the changes in composition of the mixtures become less important for compressive strength, density, and water absorption.

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Evaluation of the Effects of Coarse Aggregate Sizes on Concrete Quality

European Journal of Engineering Research and Science ◽

10.24018/ejers.2017.2.10.470 ◽

2017 ◽

Vol 2 (10) ◽

pp. 1 ◽

Cited By ~ 3

Author(s):

Lawrence Echefulechukwu Obi

Keyword(s):

Compressive Strength ◽

Coarse Aggregate ◽

Aggregate Size ◽

Test Results ◽

Construction Sites ◽

Coarse Aggregates ◽

Appreciable Increase ◽

Concrete Production ◽

Concrete Quality

This work was necessitated by the observations made at construction sites where artisans and craftsmen were left alone in concrete production. It was discovered that they used inadequate quantity and size of coarse aggregates due to difficulty associated in the mixing as if the coarse aggregates were not needed in concrete production. The research has established that the coarse aggregates and their sizes play critical roles in the development of adequate strength in concrete. It was observed that with proper mixing, the slump test results did not witness shear or collapse type of slump rather there were true slump in all cases of the test. The workability decreased with slight differences when the coarse aggregate size was increased. The increase in the coarse aggregates yielded appreciable increase in the compressive strength. It can therefore be inferred that the quality of concrete in terms of strength can be enhanced through an increase in the coarse aggregate size when proper mix ratio, batching, mixing, transporting, placing and finishings are employed in concrete productions.

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Capillary Water Absorption Characteristics of Recycled Concrete in Freeze-Thaw Environment

Advances in Materials Science and Engineering ◽

10.1155/2020/1620914 ◽

2020 ◽

Vol 2020 ◽

pp. 1-12

Author(s):

Qianhui Xiao ◽

Xiaolin Liu ◽

Jisheng Qiu ◽

Yangyang Li

Keyword(s):

Prediction Model ◽

Water Absorption ◽

Coarse Aggregate ◽

Recycled Concrete ◽

Capillary Water ◽

Replacement Rate ◽

Capillary Water Absorption ◽

Freeze Thaw ◽

Recycled Coarse Aggregate ◽

Absorption Characteristics

In order to study the capillary water absorption characteristics of recycled concrete (RAC) with different replacement rates of recycled coarse aggregate (0, 20%, 40%, and 60%) in freeze-thaw environment, the standard test method of measuring the water absorption of hydraulic cement concrete (ASTM C1585-13) was adopted, and the influence mechanism of freeze-thaw cycle and replacement rate of recycled coarse aggregate on the capillary water absorption of RAC was analyzed, and a prediction model of initial capillary water absorption of RAC in freeze-thaw environment was established. The results show that when the freeze-thaw environment is the same, the greater the replacement rate of recycled coarse aggregate, the greater the cumulative water absorption of RAC, the faster the initial capillary water absorption, and the stronger the capillary water absorption; when the freeze-thaw environment is different, the more the freeze-thaw cycles, the greater the cumulative water absorption of RAC with the same replacement rate of recycled coarse aggregate, the faster the initial capillary water absorption, and the stronger the capillary water absorption. The prediction model of RAC initial capillary water absorption established by regression analysis has high accuracy, which can be used to predict RAC capillary water absorption performance and provide theoretical basis for the research of RAC frost resistance durability.

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3-Aminopropyl-Triethoxysilane Functionalized Graphene Oxide for Silane-Based Consolidation Treatments to Increase Mortar Performances

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2021.18958 ◽

2021 ◽

Vol 21 (4) ◽

pp. 2351-2359

Author(s):

C. Cadar ◽

C. I. Fort ◽

A. Mihis ◽

Zs. Kedves ◽

K. Magyari ◽

...

Keyword(s):

Compressive Strength ◽

Graphene Oxide ◽

Water Absorption ◽

Untreated Control ◽

Mechanical Tests ◽

Capillary Absorption ◽

Capillary Water ◽

Functionalized Graphene Oxide ◽

Capillary Water Absorption ◽

Control Samples

The influence of chemically converted GO (graphene oxide) functionalized with APTES (3-aminopropyl-triethoxysilane) and unfunctionalized GO, dispersed in ethanolic solution of TEOS (tetraethyl orthosilicate), on the performances of the mortar samples, such as capillary water absorption and compressive strength was evaluated. The effect of the GO based nanomaterials (GO and GO functionalized with APTES) on the mortar microstructure was investigated by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), Raman spectroscopy and scanning electron microscopy (SEM). The multifunctionality of the mortar brushed with GO based nanomaterials consolidation suspension was proved by the results (i) of the mechanical tests which show an improvement of the compressive strength and (ii) the capillary water absorption results which indicate the decreasing of the water penetration speed. For the mortar samples brushed with GO consolidation suspension, an increase value for the compressive strength of approximately twice compared to the untreated control samples and a decreased value for the capillary absorption water coefficient with one order of magnitude in comparison with the untreated control samples were obtained.

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Use of polyvinyl chloride (PVC) powder and granules as aggregate replacement in concrete mixtures

Science and Engineering of Composite Materials ◽

10.1515/secm-2014-0094 ◽

2016 ◽

Vol 23 (2) ◽

pp. 209-216 ◽

Cited By ~ 5

Author(s):

Hakan Bolat ◽

Pınar Erkus

Keyword(s):

Mechanical Properties ◽

Compressive Strength ◽

Water Absorption ◽

Polyvinyl Chloride ◽

Physical And Mechanical Properties ◽

High Strength ◽

Capillary Water ◽

Capillary Water Absorption ◽

Concrete Mixtures ◽

Compressive Strength Test

AbstractConcrete is one of the materials in which polymer wastes are utilized. Generally, these wastes are added at specific rates in scientific studies but an important problem of waste polymers is size irregularity. Even when consistent dosage rates are used, variations in polymer size can lead to variability in the physical and mechanical properties of the concrete produced. The aim of this study is to determine physical and mechanical properties of polyvinyl chloride (PVC)-containing concretes. In order to produce normal and high strength concretes, 10%, 20%, and 30% replacement ratios of PVC powder and granules by volume of aggregate are used. Slump, fresh and hardened densities, compressive strength, capillary water absorption, and abrasion were tested on all concrete types. As the PVC ratio increases, important changes are seen in all physical and mechanical concrete properties. The unit weights of the 10%, 20%, and 30% replacement PVC powder concretes are lower by ∼4%, 8%, and 13%, respectively, as compared to the reference mixtures, and the replacement PVC granule concretes are lower by ∼2%, 4%, and 7%. Compressive strength test results showed similar trends. As PVC replacement increases, the capillary water absorption decreases between 10% and 50%, and abrasion decreases between 27% and 77%.

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Natural pozzolana addition effect on compressive strength and capillary water absorption of Mortar

Energy Procedia ◽

10.1016/j.egypro.2017.11.273 ◽

2017 ◽

Vol 139 ◽

pp. 689-695 ◽

Cited By ~ 3

Author(s):

Walid Deboucha ◽

Nordine Leklou ◽

Abdelhafid Khelidj ◽

Mohamed N. Oudjit

Keyword(s):

Compressive Strength ◽

Water Absorption ◽

Capillary Water ◽

Capillary Water Absorption ◽

Natural Pozzolana

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Influence of Crystalline Admixtures on the Short-Term Behaviour of Mortars Exposed to Sulphuric Acid

Materials ◽

10.3390/ma12010082 ◽

2018 ◽

Vol 12 (1) ◽

pp. 82 ◽

Cited By ~ 3

Author(s):

Victoria García-Vera ◽

Antonio Tenza-Abril ◽

José Saval ◽

Marcos Lanzón

Keyword(s):

Compressive Strength ◽

Absorption Coefficient ◽

Water Absorption ◽

Sulphuric Acid ◽

Cementitious Materials ◽

Pulse Velocity ◽

Capillary Water ◽

Short Term ◽

Water Absorption Coefficient ◽

Capillary Water Absorption

Using durable materials is a sustainable solution for extending the lifetime of constructions. The use of crystalline admixtures makes cementitious materials more durable. They plug pores, capillary tracts and microcracks, blocking the entrance of water due to the formation of crystals that prevent the penetration of liquids. The literature has covered the performance of these admixtures on concrete, but studies on mortars are still scarce. The aim of this study is to investigate the effect of an aggressive environment (sulphuric acid solution—3 wt%) on mortars produced with different percentages of a crystalline admixture (1%, 1.5% and 2% by weight of cement content). Physical and mechanical properties were studied after immersing the mortars in a H2SO4 solution for 90 days. It was found that, after a 90-day sulphuric acid exposure, mortars with the crystalline admixture showed greater compressive strength than the control mortar, besides exhibiting lower mass loss. However, the crystalline admixture did not produce any significant effect on the capillary water absorption coefficient. In a nonaggressive environment, and in the short term, the crystalline admixture did not have a significant effect on the compressive strength, the capillary water absorption coefficient or the ultrasonic pulse velocity.

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A Study of the Replacement of Natural Coarse Aggregate by Spherically-Shaped and Crushed Waste Cathode Ray Tube Glass in Concrete

Journal of Construction Materials ◽

10.36756/jcm.v2.1.7 ◽

2020 ◽

Vol 2 (1) ◽

Author(s):

N. N. M. Pauzi ◽

◽

M. R. Karim ◽

M. Jamil ◽

R. Hamid ◽

...

Keyword(s):

Compressive Strength ◽

Smooth Surface ◽

Coarse Aggregate ◽

Control Specimen ◽

Test Results ◽

Complete Replacement ◽

Ordinary Concrete ◽

Coarse Aggregates ◽

Optimum Proportion ◽

Cathode Ray Tube

The aim of this study is to conduct an experimental investigation on the influence of complete replacement of natural coarse aggregate with spherically-shape and crushed waste cathode ray tube (CRT) glass to the aspect of workability, density, and compressive strength of the concrete. After characterizing the glass, a group of concrete mixes was prepared to contain a 40% spherical CRT glass and 60% crushed CRT glass as a complete (100%) replacement of natural coarse aggregates. From a total of 16 types of concrete mixes, the optimum proportion was selected based on its best performance. The test results showed that the use of spherical and crushed glass that possesses a smooth surface, rounded, irregular and elongated shape, and low water absorption affects the workability of concrete. Due to a higher specific gravity of crushed glass, concrete mixes containing CRT glass had a higher density compared to ordinary concrete. Despite the spherical and crushed CRT glass being stronger than gravel, the results revealed a reduction in compressive strength of the concrete. However, using a lower water to binder (w/b) ratio and a higher superplasticizer (SP) dosage, it is found to enhance the compressive strength of 60.97 MPa at 28 days that is lower by 13% than the control specimen. These findings indicate that waste CRT glass in the form of spherical and crushed could be used as an alternative of coarse aggregate that may pave the way for the disposal of hazardous e-waste.

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Properties of Self-Compacting Mortar Containing Slag with Different Finenesses

Civil Engineering Journal ◽

10.28991/cej-2021-03091694 ◽

2021 ◽

Vol 7 (5) ◽

pp. 840-856

Author(s):

Said Kenai ◽

Siham Hammat ◽

Belkacem Menadi ◽

Jamal Khatib ◽

El-Hadj Kadri

Keyword(s):

Compressive Strength ◽

Water Absorption ◽

Yield Stress ◽

Autogenous Shrinkage ◽

The Other ◽

Mineral Admixtures ◽

Rheological Parameters ◽

Capillary Water ◽

Capillary Water Absorption ◽

Slump Flow

It is well established that Self-Compacting Concrete (SCC) contains large amounts of fines including mineral admixtures, such as fly ash and slag, in order to avoid segregation and to increase cohesion. The use of these materials in concrete reduces CO2 emissions and contributes towards sustainable construction. To overcome the negative effect of slag on the strength development slag was ground to three finenesses. Therefore, this paper examines the rheological, compressive strength, total and autogenous shrinkage and capillary water absorption of Self-Compacting Mortars (SCM) containing ground granulated blast furnace Slag (S). A total of seven mortar mixes were prepared. The control mix had a proportion of 1 (cement): 1.8 (sand): 0.38 (water). In the other mixes, the cement was partially replaced with 15% and 30% slag of different fineness of 350, 420, and 500 m2/kg. The other constituents remained unchanged. Testing included slump flow, V-funnel flow time, yield stress and viscosity, compressive strength, total and autogenous shrinkage, and capillary water absorption. The presence of slag was found to reduce the plastic viscosity and yield stress of SCM mixtures as the content and the fineness increase. The higher the fineness (specific surface) of the slag the less the rheological parameters (i.e. slump flow and viscosity). The results show also a reduction in compressive strength of SCM at early ages of curing in the presence of slag. However, in the long-term, the compressive strength of SCM mixtures containing slag was higher than that of control mortar. Generally, there is reduction in the total shrinkage and an increase in the autogenous shrinkage of SCM mixtures as the content and fineness increase. Doi: 10.28991/cej-2021-03091694 Full Text: PDF

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POROSITY, PERMEABILITY AND MICROSTRUCTURE OF FOAMED CONCRETE THROUGH SEM IMAGES

Journal of Civil Engineering Science and Technology ◽

10.33736/jcest.1434.2019 ◽

2019 ◽

Vol 10 (1) ◽

pp. 22-33 ◽

Cited By ~ 3

Author(s):

P. Shawnim ◽

F. Mohammad

Keyword(s):

Compressive Strength ◽

Water Absorption ◽

Pore Size ◽

High Porosity ◽

Capillary Water ◽

Sem Images ◽

Microstructural Investigation ◽

Capillary Water Absorption ◽

Foamed Concrete ◽

Percentage Ratio

This paper examined the foamed concrete (FC) for permeability of total and capillary water absorption, at 28 days of air sealed curing. The microstructure of 15 selected FC specimens was investigated to determine permeability in relation to porosity and density using Scanning Electron Microscopy (SEM) images. The FC specimens of the densities (1100, 1600, and 1800) kg/m3 were made using fine sand and brick aggregates with toner and MK inclusion as additives. The microstructural investigation of the FC revealed, porosity measure as a percentage ratio of the area under investigation to be in the range of (39.65 to 77.7) %. The pore size is in the range of (0.01 to 70) µm, depending on the type of additive, for the mixes containing toner and MK, it is in a fine range of (0.01 to 10.0) µm. For the FC specimens, the finer the pore size, the less permeable and the stronger it is. Permeability is porosity and strength dependent, whereby high porosity leads to high permeability and low compressive strength for FC mixes made with sand or brick only with no additive inclusion. Meanwhile, the FC mixes made with the inclusion of additives, such as the toner and MK20 mixes, showed an evenly spread net of independent air voids with a regular shape within their matrix, which is beneficial in decreasing permeability. Therefore, besides the porosity and strength, the fineness of the pore matrix and the shape factor of the pores are two other key factors in controlling permeability. Toner and MK20 inclusion can enhance the capillary water absorption to reach almost water tight. Besides, MK30 and MK50 inclusion displayed adverse effect on permeability. Depending on the type of filler, the additive, and the percentage ratio of the porosity of the FC matrix at (1600 and 1800) kg/m3 densities, it is possible to produce FC with compressive strength between (55.1 and 30) N/mm2.

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