Waste Glass Cullet Research Articles

Combined use of waste glass powder and cullet in architectural mortar

The use of 100% waste glass cullet (WGC) as fine aggregates in architectural cement-based mortar had been proven to be feasible in previous works. This paper reports a further study on investigating the influence of using waste glass powder (WGP) as a supplementary cementitious material on the properties of glass-based architectural cement mortars. The experimental results showed a good linear relationship between the particle size of WGP and the flow values of the fresh mortar, revealing that the particle size of WGP played an important role in controlling the workability. For the hydration of white cement, the inclusion of WGP not only affected the second exothermic peak of hydration but also changed the third peak. In particular, the result indicated that the use of finer WGP had an advantage in increasing the flexural strength of the cement mortar when compared with the corresponding compressive strength, which was attributed to the morphological and pozzolanic effect of WGP. In addition, the very fine WGP could act as micro-fibers and micro-aggregates in filling the microstructure of the mortar. At 90 days of curing, the mortar prepared with finer WGP showed a distinct improvement in strength due to the improved interfacial transition zone and the pore-size refinement.

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.

Fresh properties of cement pastes or mortars incorporating waste glass powder and cullet

This work was aimed at studying the fresh properties of cement-based mixtures containing waste glass powder (WGP) and waste glass cullet (WGC) obtained from crushed post-consumer beverage bottles. The experimental results show the setting time of the WGP modified pastes were prolonged due to the lower rate of hydration. Irrespective of the addition WGP, a good correlation between the early hydration characteristics and the stiffening or flowability can be established. However, during the first 30 min of hydration, the fresh properties of the WGP modified mortars were predominantly dependent on the particle size and the morphology of the WGP investigated.

Quantification of Residential Energy Consumption Reduction Using Glass-Modified Asphalt Shingle

AbstractThe urban heat island (UHI) phenomenon is defined as the differences in temperatures between urban and rural areas caused by the thermal properties of urban materials, urban geometry, and air pollution. Rooftops are playing a vital role in urban sustainability efforts and mitigating the UHI effect. Continuing these efforts, a study was conducted to evaluate the effectiveness of using recycled broken and waste glass cullet in the production of asphalt shingles to mitigate heat island effects and reduce building energy consumption by increasing the reflectivity of the roof asphalt shingles. To achieve this objective, shingle samples were prepared with and without glass cullet and the Solar Reflectance Index (SRI) of the specimens was measured based on ASTM E1980-11. The SRI of the asphalt shingles prepared with glass cullet and a white pigment powder was found to be 30, whereas it was 0 for the asphalt shingles without glass cullet. A three-dimensional transient finite-element (FE) model was formula...

Preparation and characterization of foamed geopolymers from waste glass and red mud

New foamed geopolymer materials were successfully synthesized from two waste i.e. red mud and cullet soda-glass, by thermal treatment at 600–800°C for 1h. The geopolymers were obtained by the alkali activation with sodium hydroxide solution or the liquid part of red mud slurry (filtrate) of waste glass (cullet) with/without red mud admixture.Thermal treatment of these geopolymers, at temperatures between 600 and 800°C determined an important volume increase, due to a foaming process specific for sodium silicate (aluminate) hydrates, the main components of these materials. When red mud substitutes 25% of brown glass, softening and partial melting of material occurs at higher temperatures (due to the presence of complex refractory crystalline phases with Al content); for these compositions the increase of volume due to foaming process is noticed at higher temperatures.Open pores with a wide range of sizes (1–100μm) were assessed by scanning electron microscopy; this highly porous microstructure, formed by the bubbling and coalescence of bubbles, is specific for foam materials. The compressive strength values of foamed geopolymers are in the range 2.1–8.6MPa, and as expected, decrease with the increase of open porosity.

11 Å tobermorite ion exchanger from recycled container glass

Waste container glass cullet has been evaluated as a feedstock material for the hydrothermal synthesis of tobermorite, a cation exchanger. Accordingly, it is demonstrated that essentially phase-pure 11 Å tobermorite, Ca 5 Si 6 O 16 (OH) 2 · 4H 2 O, can be obtained from a stoicheiometrically-adjusted mixture of waste glass cullet and calcium oxide in aqueous sodium hydroxide at 100ºC. A batch sorption study indicated that the cullet-derived tobermorite is highly effective in the removal of Pb 2+ (1.66 mmol g –1 ) and Cd 2+ (0.48 mmol g –1 ) from solution. Its ion exchange characteristics are compared with those of other waste-derived sorbents and potential applications are discussed.

Alkali–silica reactions of mortars produced by using waste glass as fine aggregate and admixtures such as fly ash and Li2CO3

Use of waste glass or glass cullet (GC) as concrete aggregate is becoming more widespread each day because of the increase in resource efficiency. Recycling of wastes is very important for sustainable development. When glass is used as aggregate in concrete or mortar, expansions and internal stresses occur due to an alkali-silica reaction (ASR). Furthermore, rapid loss in durability is generally observed due to extreme crack formation and an increase in permeability. It is necessary to use some kind of chemical or mineral admixture to reduce crack formation. In this study, mortar bars are produced by using three different colors of glass in four different quantities as fine aggregate by weight, and the effects of these glass aggregates on ASR are investigated, corresponding to ASTM C 1260. Additionally, in order to reduce the expansions of mortars, 10% and 20% fly ash (FA) as mineral admixture and 1% and 2% Li(2)CO(3) as chemical admixture are incorporated by weight in the cement and their effects on expansion are examined. It is observed that among white (WG), green (GG) and brown glass (BG) aggregates, WG aggregate causes the greatest expansion. In addition, expansion increases with an increase in amount of glass. According to the test results, it is seen that over 20% FA and 2% Li(2)CO(3) replacements are required to produce mortars which have expansion values below the 0.2% critical value when exposed to ASR. However, usages of these admixtures reduce expansions occurring because of ASR.

Performance of photo-catalytic paving blocks made from waste

Preliminary studies at The Hong Kong Polytechnic University showed that concrete paving blocks made from local waste materials (including construction/demolition waste and waste glass cullet) can be used to remove nitrous oxide (NO) when titanium dioxide (TiO2) was incorporated in the mix design. To determine the effectiveness of the photo-catalytic paving block when used in field conditions, a batch of factory-produced photo-catalytic paving blocks was produced and used in an actual site trial. The air quality of the field testing site was continuously monitored to analyse the effect of the blocks towards the surrounding air quality. The observations showed that nitrogen oxide (NOx) concentrations were reduced by 13% at ground level and by 10% at the breathing zone. After a period of four months the blocks were removed from test site and taken back to the laboratory to analyse whether their ability to remove NO had been degraded. The results showed a decrease in performance of 23%, which is low compared with tests on similar products.

Waste glass and fly ash derived glass-ceramic

Crystallization behavior of a waste-based glass-ceramic was studied by means of X-ray diffraction analysis, and the surface morphological observations and chemical compositions were evaluated by field emission-scanning electron microscopy and energy dispersive X-ray spectrometry. Applying the mechanical milling method, the glass-ceramic was prepared by using fly ash from a thermal power plant mixed with waste glass cullet. Powder mixtures consisting of waste glass powder (70 wt%) and fly ash (30 wt%) were used to make glass-ceramic. Various heat treatment temperatures [900, 925, 950, 975, 1000 and 1025°C] were used to obtain a glass-ceramic of the optimum crystal phase, mechanical properties and chemical durability. The X-ray diffraction analysis showed that the crystalline phases in the glass-ceramic were diopside [Ca(Mg, Al)(Si, Al)2O6], augite [Ca(Mg, Fe)Si2O6] and wollastonite [CaSiO3]. The crystallization of an acicular phase in the matrix was achieved in the heat treatment temperature range of 1000–1025°C, and the acicular type main crystal phase in the glass-ceramic was wollastonite [CaSiO3]. The heat treatment temperature range [1000–1025°C] also showed much better mechanical properties.

Effects of contaminants on the properties of concrete paving blocks prepared with recycled concrete aggregates

The use of recycled aggregates for preparing concrete products has been successfully implemented and gaining wider acceptance. However, the allowable level of contaminating materials (e.g., crushed clay bricks, crushed ceramic tiles, waste glass cullet, wood chips, etc.) in the recycled concrete aggregate, in the some of the current specifications, is low (<1%) due to stringent quality control standards that are usually taken from specifications for raw granular virgin materials. This paper presents a recent study on the properties of concrete paving blocks prepared with recycled concrete aggregates that are contaminated by materials (tiles, clay bricks, glass, wood) commonly found in the construction and demolition waste. The density, compressive strength, tensile splitting strength, water absorption value, abrasion resistance, skid resistance and some durability parameters were measured for laboratory prepared samples. The results show that it is feasible to allow a higher level of contamination in the recycled concrete aggregates for making the concrete products. Recommendations are made on how the specifications could be revised to facilitate a wider application of recycled aggregates that is contaminated by foreign materials.

Effect of additional materials on the properties of glass-ceramic produced from incinerator fly ashes

There are 21 Metro-waste incinerators in Taiwan under construction and are expected to be finished at year 2003. It is estimated that these incinerators will produce about two million tons of incinerator ash. In order to reduce the volume and eliminate contamination problems, high temperature molten technology studies have been conducted. The purpose of this research was that of trying to control the chemical composition of the glass-ceramic produced from incinerator fly ash, in order to improve the characteristics of the glass-ceramic. The experimental results showed that the additional materials, Mg(OH) 2 and waste glass cullet, can change glass-ceramic phases from gehlenite to augite, pigeonite, and diopside. The physical, mechanical and chemical resistance properties of the glass-ceramic also showed much better characteristics than prepared glass-ceramic using incinerator fly ash alone.

The collection and recycling of waste glass (cullet) in glass container manufacture

Recovering glass for recycling is receiving renewed attention in many countries as a method of reducing the volume of solid waste and the consumption of raw materials. In the process of an analysis of the economic and technical constraints which have to be met, the paper describes the contamination levels and the plant needed to meet them, gives an account of the supply and demand position as well as a typical breakdown of the costs associated with the recovery and cleaning of waste glass. After discussing the potential for energy saving and the risks in replacing raw materials by recycled glass, there is a description of a successful U.K. glass recycling system introduced in 1977 modelled on similar schemes introduced in other European countries.

The recovery of waste glass cullet for recycling purposes by means of electro-optical sorters

The background to waste glass recovery is discussed and suitable electro-optical machinery for the reclamation process described. Machinery performance is quoted in relation to typical glass users' specifications, and the system is evaluated economically on the basis of a suggested installation flow diagram. Conclusions are drawn as to the effectiveness of the machines in upgrading waste cullet to an acceptable commercial standard and to the profitability of the process.