Waste Glass Aggregate Research Articles

Valorization of recycled materials in development of self-compacting concrete: Mixing recycled concrete aggregates – Windshield waste glass aggregates

Abstract The presented paper is based on a comparative experimental study aimed to incorporate coarse recycled concrete aggregates (RCA) and coarse recycled glass aggregates (RGA) from waste glass “windshield” in the composition of self-compacting concrete (SCC). The main objective is to study the influence of these aggregates on fresh and hardened concrete properties. In order to reach this purpose, two series of SCC mixes were prepared by replacing natural coarse aggregates (NCA) by RCA and RCA by RGA. The key properties of SCC recommended by European specifications and guidelines (EFNARC), were measured in the fresh state. While the compressive strength, water absorption testing and the observations on cross-section to evaluate the stability and segregation potential, were conducted on hardened concretes. For replacement of NCA by RCA, the use in SCC fine and coarse recycled concrete aggregates is not advisable, the flowability criteria cannot be ensured. The experimental results showed that the slump flow test has given a diameter of 610 mm. Likewise, also the L-box blocking ratio was limited to 0.2. The replacement of RCA by RGA did not significantly affect the initial slump, the obtained values are all above the minimum threshold of 650 mm. EFNARC criterion of passing ability is also satisfied. The yield stress and the plastic viscosity, determined by empirical equations, are in agreement with those observed with traditional SCC. The compressive strength of the RGA–SCC mixes decreased with an increase in recycled glass content but remain within the strength range of self-compacting concretes. The results have showed that it is possible to produce SCC with windshield waste glass aggregates.

Effect of Magnetized Water on the Mechanical Properties of Concrete Containing Recycled Waste Glass Aggregate

Concrete use is fundamental to most infrastructural development plan of humanity today. This underscores the need to understand the strength characteristics of concrete made with crushed glass aggregate as partial replacement for fine aggregate and mixed with magnetic field treated water (MFTW). This study investigates the mechanical properties of concrete mixes prepared and cast into cubes of varying constituents such as concrete mixed with normal water, concrete mixed with MFTW, concrete with varying degree of crushed glass as replacement of fine aggregate from 15 to 45% with or without MFTW. The cubes were thereafter crushed after 7, 14, 28 and 56 days of curing to determine their compressive and tensile strengths. From the results obtained, it was observed that the optimum percentage partial replacement of sand with crushed glass aggregate is 15% to attain a suitable using MFTW in the mixing of the concrete. At this percentage replacement, it was observed that both the compressive and tensile strengths of the concrete mixed with MFTW improved by 25-30% relative to the conventional concrete. The study therefore recommend the use of MFTW in place of normal water in concrete production and use especially when partially replacing fine aggregate with crushed glass aggregate.

A study on the potential use of paper sludge ash in concrete with glass aggregate.

This short communication focuses on the potential use of paper sludge ash, a waste product of the paper making industry, as an innovative binder partially replacing cement in concrete with glass aggregate. After preliminary testing using binary or ternary CEM-II mixes with paper sludge ash/pulverised fly ash, a suitable mix for concrete with glass aggregate was identified. Concrete mixes with partial or full natural sand replacement by waste glass aggregate were then produced and showed appropriate strengths and overall similar or better water absorption characteristics than control mixes with natural aggregates, without manifest alkali-silica reaction problems. This shows potential for applications in precast dry mix concrete units based on the required strengths that were achieved.

Reduced alkali-silica reaction damage in recycled glass mortar samples with supplementary cementitious materials

Recycling waste glass aggregate into concrete can reduce environmental impacts but also may lead to serious alkali silica reaction (ASR) damage. This study aims to characterize ASR damage development in the mortar samples containing reactive glass aggregates and investigate the damage reduction effect of the waste supplementary cementitious materials (SCMs), including recycled glass powders and fly ash. The recycled glass aggregate mortar samples with/without SCMs were prepared in this study. The length change tests were first conducted with the prepared mortar samples based on the ASTM C1260 standard. The results demonstrated the added SCMs can largely decrease early-age ASR expansion rate. The optical microscope and Scanning Electron Microscope (SEM) with Energy Dispersive X-ray Spectroscopy (EDS) were further conducted to characterize the ASR damage in mortar samples and investigate the damage mitigation mechanism with added SCMs. The combined SEM imaging and chemical analysis indicated added SCMs can decrease both the alkali and calcium content of the generated ASR gel. In addition, the ASR damage development inside mortar samples were monitored with dynamic micron X-ray CT (μCT) over a reaction period of 63 h at the temperature of 80 °C. The scanning patterns demonstrated the ASR damage can be easily developed from the area with initial cracks and sharp corners. The images of glass power and fly ash samples showed significantly reduced ASR damage. This study showed that adding of SCMs can largely reduce ASR deterioration and thus facilitate the recycling glass particles into concrete.

Evaluation of the Effects of Crushed and Expanded Waste Glass Aggregates on the Material Properties of Lightweight Concrete Using Image-Based Approaches.

Recently, the recycling of waste glass has become a worldwide issue in the reduction of waste and energy consumption. Waste glass can be utilized in construction materials, and understanding its effects on material properties is crucial in developing advanced materials. In this study, recycled crushed and expanded glasses are used as lightweight aggregates for concrete, and their relation to the material characteristics and properties is investigated using several approaches. Lightweight concrete specimens containing only crushed and expanded waste glass as fine aggregates are produced, and their pore and structural characteristics are examined using image-based methods, such as scanning electron microscopy (SEM), X-ray computed tomography (CT), and automated image analysis (RapidAir). The thermal properties of the materials are measured using both Hot Disk and ISOMET devices to enhance measurement accuracy. Mechanical properties are also evaluated, and the correlation between material characteristics and properties is evaluated. As a control group, a concrete specimen with natural fine sand is prepared, and its characteristics are compared with those of the specimens containing crushed and expanded waste glass aggregates. The obtained results support the usability of crushed and expanded waste glass aggregates as alternative lightweight aggregates.

Study of Bond Characteristics of Reinforced Waste Glass Aggregate Concrete

The conformity of properties of waste glass aggregate with conventional aggregate was found out. Nine cubes (150mm x 150mm x 150mm) were cast out of which three were used for control concrete, three were fully replaced with waste glass as coarse aggregate, three were partially replaced(50%) with waste glass as fine aggregate. Six cylinders (150mm x 300mm) were cast out of which two for control concrete, two cylinders with coarse aggregate fully replaced with waste glass aggregate(WGA) and remaining two cylinders with partially replaced (50%) fine aggregate with waste glass aggregate. Cured specimens were subjected to compression and split-tensile test to ascertain the characteristic compressive strength and split tensile strength. Since the surface of the coarse aggregate plays a significant role in bonding of the rebar in reinforced concrete, pull-out test on both control and Waste Glass Aggregate (WGA) cube specimens (150mm x 150mm with 20mm diameter steel rods) were conducted. Scanning Electron Microscopy (SEM) analysis has been done for better understanding of bonding properties in waste glass fine aggregate(WGFA) and waste glass coarse aggregate(WGCA) concrete. Comparison of the results with that of control specimens showed that waste glass could be effectively used as aggregates in reinforced concrete construction.

Thermal Properties of Cement Mortars Containing Waste Glass Aggregate and Nanosilica

In recent years utilization of solid waste in building materials has gathered spectacular attention. One material with potential applications, especially in cement-based composites, is waste glass. The aim of this study was to evaluate the possibility of manufacturing sustainable cement mortars with the use of nanosilica (NS) and brown soda-lime waste glass (WG) fine aggregate. The mechanical and thermal properties of cement mortars containing WG aggregate and nanosilica, were analyzed in terms of waste glass and nanosilica content. Ordinary fine aggregate (river sand) was replaced with WG fine aggregate at a ratio of 100% by weight. Moreover, 0, 1 and 3 wt% of NS was incorporated to cement mortar. The experiment revealed that the presence of WG fine aggregate significantly decreased the thermal conductivity of the cement mortars and that furthermore, the sorptivity coefficient decreased. The study has shown that WG fine aggregate can be a successful substitute for natural fine sand without leading to mechanical deterioration and by significantly improving thermal properties of cement mortars. Additionally, the incorporation of nanosilica (especially in higher contents – 3 wt%) leads to a further decrement in thermal conductivity and sorptivity and improves compressive strength.

Strengths and Failure Characteristics of Self-Compacting Concrete Containing Recycled Waste Glass Aggregate

The effects of different proportions of green-colored waste glass (WG) cullet on the mechanical and fracture properties of self-compacting concrete (SCC) were experimentally investigated. Waste bottles were collected, washed, crushed, and sieved to prepare the cullet used in this study. Cullet was incorporated at different percentages (0%, 20%, 40%, 60%, 80%, and 100% by weight) instead of natural fine aggregate (NFA) and/or natural coarse aggregate (NCA). Three SCC series were designed with a constant slump flow of700±30 mm, total binder content of 570 kg/m3and at water-to-binder (w/b) ratio of 0.35. Moreover, fly ash (FA) was used in concrete mixtures at 20% of total binder content. Mechanical aspects such as compressive, splitting tensile, and net flexural strengths and modulus of elasticity of SCC were investigated and experimentally computed at 28 days of age. Moreover, failure characteristics of the concretes were also monitored via three-point bending test on the notched beams. The findings revealed that the mechanical properties as well as fracture parameters were adversely influenced by incorporating of WG cullet. However, highest reduction of compressive strength did not exceed 43% recorded at 100% WG replacement level. Concretes containing WG showed less brittle behavior than reference concrete at any content.

Characterization of Mechanical and Bactericidal Properties of Cement Mortars Containing Waste Glass Aggregate and Nanomaterials.

The recycling of waste glass is a major problem for municipalities worldwide. The problem concerns especially colored waste glass which, due to its low recycling rate as result of high level of impurity, has mostly been dumped into landfills. In recent years, a new use was found for it: instead of creating waste, it can be recycled as an additive in building materials. The aim of the study was to evaluate the possibility of manufacturing sustainable and self-cleaning cement mortars with use of commercially available nanomaterials and brown soda-lime waste glass. Mechanical and bactericidal properties of cement mortars containing brown soda-lime waste glass and commercially available nanomaterials (amorphous nanosilica and cement containing nanocrystalline titanium dioxide) were analyzed in terms of waste glass content and the effectiveness of nanomaterials. Quartz sand is replaced with brown waste glass at ratios of 25%, 50%, 75% and 100% by weight. Study has shown that waste glass can act as a successful replacement for sand (up to 100%) to produce cement mortars while nanosilica is incorporated. Additionally, a positive effect of waste glass aggregate for bactericidal properties of cement mortars was observed.

Waste glass aggregate for cementitious and polymer concrete

Glass waste is produced in considerable amounts annually. Due to the disadvantageous nature of its recycling process, its reuse gains importance. Given the high reactivity level of glass-incorporating mixtures, the reuse of waste glass as aggregate in polymer concrete was investigated. Polymer concrete mixtures, including unsaturated polyester resin, hardener and accelerator, waste glass aggregate (up to 8 mm) and glass fabrics, were prepared for the investigation of mechanical properties. The composite specimens were reinforced by means of glass fabrics in various types (woven or mat), amounts (single or double layer) and orientation (perpendicular or parallel to loading direction). The mechanical properties of polymer concretes were tested for flexural tensile strength and compressive strength. In addition, thermal conductivity and residual strength after elevated temperatures were determined. It was concluded that these composites with easy preparation techniques have superior mechanical and thermal insulation properties compared with their counterparts available for use and their mechanical properties were mainly affected by the amount, type and orientation of the glass fabric reinforcement.

Inhibitory Effect of Waste Glass Powder on ASR Expansion Induced by Waste Glass Aggregate.

Detailed research is carried out to ascertain the inhibitory effect of waste glass powder (WGP) on alkali-silica reaction (ASR) expansion induced by waste glass aggregate in this paper. The alkali reactivity of waste glass aggregate is examined by two methods in accordance with the China Test Code SL352-2006. The potential of WGP to control the ASR expansion is determined in terms of mean diameter, specific surface area, content of WGP and curing temperature. Two mathematical models are developed to estimate the inhibitory efficiency of WGP. These studies show that there is ASR risk with an ASR expansion rate over 0.2% when the sand contains more than 30% glass aggregate. However, WGP can effectively control the ASR expansion and inhibit the expansion rate induced by the glass aggregate to be under 0.1%. The two mathematical models have good simulation results, which can be used to evaluate the inhibitory effect of WGP on ASR risk.

Research on Waste Glass Concrete Elasticity Modulus

Waste glass is an industrial waste and household garbage, having a "flash color pollution" notoriety. Although some white glass can be processed into glass again, however, low utilization. But much of the waste glass still cannot be recycled. The key to improve the utilization of waste glass is how to effectively use colored and mixed waste glass. Waste glass aggregate concrete as a new material, the study of its basic performance is not mature. Taking into account the impact of different glass replacement rate on their basic mechanical properties, this paper tests carried out static compressive elasticity modulus test with glass concrete. Study the mechanical properties and deformation performance of glass concrete columns the basis of its basic mechanical properties, in order to obtain the glass concrete column of structure performance parameters.

Mechanical properties and ASR evaluation of concrete tiles with waste glass aggregate

This work describes a statistical design of experiments (DoE) testing campaign on 396 samples to evaluate the effect of replacing quartz aggregate in concrete with waste glass, and Portland cement with metakaolin to develop a novel generation of sustainable concrete tiles. The properties assessed were bulk density, permeability, dynamic modulus and length changes due to alkali-silica reaction (ASR) expansion. Metakaolin (MK) was used to replace Portland cement (PC) to verify the possibility of obtaining lower ASR expansion. Higher permeability and lower bulk density were obtained when the quartz was replaced with glass particles. The statistical analysis also confirmed that the dispersion of 15wt% of MK was able to mitigate any possible ASR expansion caused by the presence of coarse glass particles. The composite mixes evaluated in this work constitute promising materials to be used in concrete tiles or similar semi-dry compacted products.

Research on Waste Glass Concrete Basic Mechanical Property

Glass has the characteristics of biologically incapable of breaking down, corrosion resistant, suitable for long term storage and use. It has resistance of acid, alkali and salt and stable property. The hardness of the natural stone with the glass is very close , therefore, the waste glass as fine aggregate instead of natural sand to produce concrete is feasible. This paper use ordinary concrete C30 as the research object normal concrete using mixed glass method design, in accordance with the percentage of 0, 50, 100 instead of sand. Three sections and eighteen waste glass aggregate concrete specimens were produced for the cube concrete compressive strength and the axial compressive strength experiments. Through the analysis of experimental data, it suggested that the ratio of glass replacing sand is higher ,the compressive strength and the axial compressive strength are higher.

Heat and mechanical properties of waste glass aggregate as a base course material for taking measures of heat island

Heat and mechanical properties of waste glass aggregate as a base course material for taking measures of heat island

Studies on mechanical properties of concrete containing waste glass aggregate

Quantities of waste glass have been on the rise in recent years due to an increase in industrialization and the rapid improvement in the standard of living. Unfortunately, the majority of waste glass is not being recycled but rather abandoned, and is therefore the cause of certain serious problems such as the waste of natural resources and environmental pollution. For these reasons, this study has been conducted through basic experimental research in order to analyze the possibilities of recycling waste glasses (crushed waste glasses from Korea such as amber, emerald green, flint, and mixed glass) as fine aggregates for concrete. Test results of fresh concrete show that both slump and compacting factors are decreased due to angular grain shape and that air content is increased due to the involvement of numerous small-sized particles that are found in waste glasses. In addition the compressive, tensile and flexural strengths of concrete have been shown to decrease when the content of waste glass is increased. In conclusion, the results of this study indicate that emerald green waste glass when used below 30% in mixing concrete is practical along with usage of 10% SBR latex. In addition, the content of waste glasses below 30% is practical along with usage of a pertinent admixture that is necessary to obtain workability and air content.

“Glascrete”—Concrete with Glass Aggregate

Post-consumer glass represents a major component of solid waste, yet its use as an aggregate in concrete is problematic because of the strong alkali-silica reaction (ASR) between the cement paste and the glass aggregate. In a research project at Columbia University, the use of crushed waste glass as aggregate for concrete products was investigated. Fundamental aspects of ASR in concrete with glass aggregate were studied. It was shown that waste glass ground to U.S. standard sieve size No. 50 or smaller causes mortar bar expansions in the American Society for Testing and Materials C 1260 test of less than 0.1%, which is less than that of reference bars without any glass. Also, green glass does not cause any expansion to speak of, and finely ground green glass has the potential of an inexpensive ASR suppressant. Specific concrete products with glass aggregate are currently under development. These include concrete masonry blocks with 10% mixed color waste glass aggregate and glascrete products with 100% color-sorted glass aggregate for numerous architectural applications.