scholarly journals Waste Wash-Water Recycling in Ready Mix Concrete Plants

Environments ◽  
2020 ◽  
Vol 7 (12) ◽  
pp. 108
Author(s):  
Ayoup M. Ghrair ◽  
Andrew Heath ◽  
Kevin Paine ◽  
Muath Al Kronz
Keyword(s):  
Water Samples ◽  
Pilot Plant ◽  
Wash Water ◽  
Settling Pond ◽  
Concrete Mixtures ◽  
Concrete Production ◽  
Filtration Unit ◽  
Ready Mixed Concrete ◽  
Mixing Water ◽  
Ready Mix Concrete

The management of waste wash-water (WWW) is one of the most significant environmental problems associated with ready-mix concrete production worldwide. The problems are exacerbated should it be disposed of in an inappropriate manner. This study evaluated the potential of WWW recycling in ready mix concrete plants in Jordan. A representative waste wash-water sample (400 L) was collected from a basin in a ready-mix concrete company. A pilot plant on the lab scale was fabricated and installed. The treatment system consisted of a concrete washout reclaimer, wedgebed slurry settling pond, slow sand filtration unit, and a neutralization unit. Water samples were collected from all stages of the pilot plant and analyzed. The collected waste wash-water samples were utilized for replacement of well water (mixing water) at various ratios. Fourteen concrete mixtures were produced and cast, as well as tested at various curing ages (7, 28, and 90 days). The results show that the raw WWW was not acceptable as mixing water even after dilution as it led to significant reductions in concrete compressive strength and low workability. However, the WWW from the settling pond, the filtered WWW and the filtered-neutralized WWW at dilution ratios up to 75% were shown to be potential alternatives to fresh water for ready-mixed concrete. Therefore, the current guidelines for mixing water quality should be revised to encourage the reuse of the WWW.

scholarly journals The Using of Concrete Wash Water from Ready Mixed Concrete Plants in Cement Systems

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2483
Author(s):  
Danutė Vaičiukynienė ◽  
Aras Kantautas ◽  
Simona Tučkutė ◽  
Fallon Manhanga ◽  
Eugenijus Janavičius ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fresh Concrete ◽  
Negative Impact ◽  
Tap Water ◽  
Pozzolanic Reaction ◽  
Wash Water ◽  
Complex Chemical ◽  
Concrete Mixtures ◽  
Complex Chemical Reactions ◽  
Ready Mixed Concrete

Concrete plants accumulate large amounts of concrete wash water. This water, which pH is highly alkaline, has a negative impact on the environment. Its reuse in fresh concrete slightly reduces its mechanical properties. The combination of concrete wash water and zeolitic by-product led to an increase of 4.6% in the compressive strength at 7 days hydration and up to 30% at 28 days hydration. The same combination led to the denser microstructure compared to the samples made with concrete wash water. This could be explained by the pozzolanic reaction of the zeolitic by-product. The complex chemical reactions of cement, zeolitic by-product, and fines presented in the concrete wash water occurred. Therefore, it was suggested the reusing method of concrete wash water together with zeolitic by-product in the fresh concrete mixtures by substituting some amount of tap water with concrete wash water. In this way, the consumption of tap water is possible to reduce in cement systems.

scholarly journals NRG COSIA Carbon XPRIZE: carbon-dioxide mineralization in recycled concrete wash water

Clean Energy ◽  
2021 ◽  
Vol 5 (4) ◽  
pp. 553-574
Author(s):  
Sean Monkman ◽  
Travis Janke ◽  
Alex Hanmore
Keyword(s):  
Suspended Solids ◽  
Cement Hydration ◽  
Setting Time ◽  
Recycled Concrete ◽  
Wash Water ◽  
Concrete Production ◽  
Carbon Dioxide Mineralization ◽  
A Site ◽  
Ready Mixed Concrete ◽  
Co2 Treatment

Abstract Wash water is generated as a waste stream from ready-mixed-concrete production. Reuse of the water as mixture water is limited, in practice, by the negative material performance impacts associated with the water chemistry and properties; the effects are intensified with increasing content of suspended solids and age. However, this waste material can be used as a beneficial additive to concrete by profiting from the cementitious properties of the suspended solids, if variability can be reduced. A method of stabilizing this material is through CO2 treatment. The added CO2 is mineralized through a reaction with the calcium from the cement particles. This provides a calcium-carbonate coating that prevents further cement hydration, making the material predictable. This has been shown to alleviate concerns with set acceleration and inconsistencies in compressive strength. A method of CO2 treatment was tested as part of the NRG COSIA Carbon XPRIZE at a site in Calgary, Alberta. The slurry for the treatment was provided by a local concrete plant and had a specific gravity of 1.15. The simulated wash water was treated in 1000-L quantities with each treatment mineralizing an average of 40 kg of CO2. The system ran for 1600 hours of operation over 127 treatment cycles and converted 14.5 tonnes of CO2 at an average mineralization efficiency of 80%. The treated slurry was used as an additive in >300 batches of concrete where the concrete met the necessary requirements for fresh properties and setting time, while achieving a strength benefit. Replacement of 5% and 10% of batch water with treated slurry (9.4 and 18.8 kg slurry/m3 concrete) showed a strength benefit of 3% and 6% compared to a reference. The technology was selected as the winner of the NRG COSIA Carbon XPRIZE (Track B: Natural Gas) in April 2021.

scholarly journals Feasibility of Eco-Friendly Binary and Ternary Blended Binders Made of Fly-Ash and Oil-Refinery Spent Catalyst in Ready-Mixed Concrete Production

2018 ◽  
Vol 10 (9) ◽  
pp. 3136 ◽  
Author(s):  
Carla Costa ◽  
José Marques
Keyword(s):  
Large Scale ◽  
Construction Materials ◽  
International Standards ◽  
Oil Refinery ◽  
Industrial Wastes ◽  
Spent Catalyst ◽  
Concrete Production ◽  
Ready Mixed Concrete ◽  
Binary Blended Concrete ◽  
Mixed Concrete

Large-scale recycling of new industrial wastes or by-products in concrete has become a crucial issue for construction materials sustainability, with impact in the three pillars (environmental, social and economic), while still maintaining satisfactory, or improved, concrete performance. The main goal of the paper is to evaluate the technological feasibility of the partial, or total, replacement of fly-ashes (FA), widely used in ready-mixed concrete production, with spent equilibrium catalyst (ECat) from the oil-refinery industry. Three different concrete mixtures with binary binder blends of FA (33.3% by mass, used as reference) and of ECat (16.7% and 33.3%), as well as a concrete mixture with a ternary binder blend with FA and ECat (16.7%, of each) were tested regarding their mechanical properties and durability. Generically, in comparison with commercial concrete (i) 16.7% ECat binary blended concrete revealed improved mechanical strength and durability; (ii): ternary FA-ECat blended binder concrete presented similar properties; and (iii) 33% ECat binary blended concrete has a lower performance. The engineering performance of all ECat concretes meet both the international standards and the reference durability indicators available in the scientific literature. Thus, ECat can be a constant supply for ready-mixed eco-concretes production, promoting synergetic waste recycling across industries.

scholarly journals Evaluation of Environmental Requirements for Sustainable Ready-Mix Concrete Production in Abu Dhabi Emirate

2014 ◽  
Vol 05 (04) ◽  
pp. 333-339
Author(s):  
Ghanim Kashwani ◽  
Abeer Sajwani ◽  
Muhammad Al Ashram ◽  
Rahma Al Yaaqoubi
Keyword(s):  
Abu Dhabi ◽  
Concrete Production ◽  
Abu Dhabi Emirate ◽  
Environmental Requirements ◽  
Ready Mix Concrete

Quantification of geographical proximity of sugarcane bagasse ash sources to ready-mix concrete plants for sustainable waste management and recycling

2020 ◽  
pp. 0734242X2094537 ◽  
Author(s):  
Gopinath Athira ◽  
Abdulsalam Bahurudeen ◽  
Vijaya Sukumar Vishnu
Keyword(s):  
Fly Ash ◽  
Sugarcane Bagasse ◽  
Raw Materials ◽  
Disposal Site ◽  
Partial Replacement ◽  
Geographic Proximity ◽  
Study Results ◽  
Concrete Production ◽  
Sugarcane Bagasse Ash ◽  
Ready Mix Concrete

As stated in the European Commission’s waste framework directive, the geographic proximity of wastes to the potential recovery/disposal site is of paramount importance in attaining an effective resource recycling paradigm. The global interest in achieving an end-of-waste scenario encourages the recovery of useful products/secondary raw materials from locally available waste materials. Sugarcane bagasse ash is an abundantly available waste (44,200 tonnes day–1) from sugar plants in India which has the potential to be used as a partial replacement to cement in ready-mix concrete plants. Although pozzolanic performance of sugarcane bagasse ash and its ability in reducing the carbon emissions associated with concrete production have been reported in earlier research studies, its use in concrete is hindered due to the lack of availability and accessibility data. In this study, the geographical distribution of sugar plants and the available quantity of sugarcane bagasse ash in India have been determined. In addition, a detailed network analysis using a geographic information system was conducted to quantify the geographic proximity of bagasse ash, fly ash and slag sources to ready-mix concrete plants. The study results indicate that for most of the ready-mix concrete plants in India, the probability of having a bagasse ash source in proximity is higher than the probability of encountering slag/fly ash sources.

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

2018 ◽  
Vol 10 (11) ◽  
pp. 3862 ◽  
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.

Factors affecting pouring ready mix concrete production rate using tower cranes in Egypt

2011 ◽  
Vol 3 (4) ◽  
pp. 353
Author(s):  
Emad El Maghraby ◽  
Jan Frick ◽  
Christopher Irgens
Keyword(s):  
Production Rate ◽  
Factors Affecting ◽  
Concrete Production ◽  
Ready Mix Concrete

Leaching behaviour of municipal solid waste incineration bottom ash: From granular material to monolithic concrete

2017 ◽  
Vol 35 (9) ◽  
pp. 978-990 ◽  
Author(s):  
Sabrina Sorlini ◽  
Maria Cristina Collivignarelli ◽  
Alessandro Abbà
Keyword(s):  
Municipal Solid Waste ◽  
Solid Waste ◽  
Bottom Ash ◽  
Waste Incineration ◽  
Municipal Solid Waste Incineration ◽  
Concrete Mixtures ◽  
Concrete Production ◽  
Critical Issues ◽  
Leaching Behaviour ◽  
Natural Aggregates

The aim of this work was to assess the leaching behaviour of the bottom ash derived from municipal solid waste incineration (MSWI) used in concrete production. In particular, the release of pollutants was evaluated by the application of different leaching tests, both on granular materials and monolithic samples (concrete mixtures cast with bottom ash). The results confirmed that, according to Italian regulations, unwashed bottom ashes present critical issues for the use as alternative aggregates in the construction sector due to the excessive release of pollutants; instead, the leachate from washed bottom ashes was similar to natural aggregates. The concentration of pollutants in the leachate from concrete mixtures was lower than regulation limits for reuse. The crushing process significantly influenced the release of pollutants: this behaviour was due both to the increase in surface area and the release of contaminants from cement. Moreover, the increase in contact time (up to 64 days) involved more heavy metals to be released.

Treatment of taste and odor causing substances in drinking water

1997 ◽  
Vol 35 (8) ◽  
pp. 29-36 ◽  
Author(s):  
Youngsug Kim ◽  
Yeongho Lee ◽  
Chai S. Gee ◽  
Euiso Choi
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Iodine Number ◽  
Water Samples ◽  
Pilot Plant ◽  
Raw Water ◽  
Process Scheme ◽  
Taste And Odor ◽  
Detectable Concentration ◽  
Removal Efficiencies

To collect fundamental data for the improvement of drinking water quality, focusing on the removal of 2-MIB, Geosmin, IPMP, IBMP and TCA, a total of 20m3/d pilot plant was operated with process schemes of GAC with post-O3(PP-I), and without ozonation(PP-II). Five taste and odor causing substances could be removed to non-detectable concentration with PP-I, but GAC alone was not so effective as PP-I. The larger the EBCT and Iodine Number of GAC column employed, the higher the removal efficiencies expected. The minimum EBCT and Iodine Number were respectively 15 min and 1,000 mg/g of GAC column. Geosmin removal efficiencies ranged 30 to 40% at 15.6 ng/l during conventional process scheme, but 70 to 80% removal was achieved by the PP-I and 60 to 70% by PP-II was achieved. IPMP removal efficiencies were 60 to 80% with GAC only. IBMP and TCA were seldom detected in raw water samples, but TCA was the most difficult to remove of five taste and odor causing substances.

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