Wet-milling disposal of autoclaved aerated concrete demolition waste – A comparison with classical supplementary cementitious materials

2020 ◽  
Vol 31 (9) ◽  
pp. 3736-3746
Author(s):  
Jin Yang ◽  
Linghao Zeng ◽  
Zechun Su ◽  
Xingyang He ◽  
Ying Su ◽  
...  
Keyword(s):  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Wet Milling ◽  
Demolition Waste ◽  
Autoclaved Aerated Concrete ◽  
Aerated Concrete

scholarly journals Detoxified Spent Pot Lining from Aluminum Production as (Alumino-)Silicate Source for Composite Cement and AutoClaved Aerated Concrete

2021 ◽  
Vol 11 (8) ◽  
pp. 3715
Author(s):  
Arne Peys ◽  
Mateja Košir ◽  
Ruben Snellings ◽  
Ana Mladenovič ◽  
Liesbeth Horckmans
Keyword(s):  
Fly Ash ◽  
Chemical Reactivity ◽  
Coal Fly Ash ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Aluminum Production ◽  
Strength Development ◽  
Autoclaved Aerated Concrete ◽  
Concrete Blocks ◽  
Aerated Concrete

New sources of supplementary cementitious materials (SCMs) are needed to meet the future demand. A potential new source of SCM is spent pot lining, a residue from aluminum production. The present work showed that the refined aluminosilicate part of spent pot lining (SPL) has a moderate chemical reactivity in a cementitious system measured in the R3 calorimetry test, comparable to commercially used coal fly ash. The reaction of SPL led to the consumption of Ca(OH)2 in a cement paste beyond 7 days after mixing. At 28 and 90 days a significant contribution to strength development was therefore observed, reaching a relative strength, which is similar to composite cements with coal fly ash. At early age a retardation of the cement hydration is caused by the SPL, which should most likely be associated with the presence of trace amounts of NH3. The spent pot lining is also investigated as silica source for autoclaved aerated concrete blocks. The replacement of quartz by spent pot lining did not show an adverse effect on the strength-density relation of the lightweight blocks up to 50 wt% quartz substitution. Overall, spent pot lining can be used in small replacement volumes (30 wt%) as SCM or as replacement of quartz (50 wt%) in autoclaved aerated concrete blocks.

scholarly journals Non-autoclaved aerated concrete made of modified binding composition containing supplementary cementitious materials

2014 ◽  
Vol 13 (2) ◽  
pp. 127-134 ◽  
Author(s):  
Oksana Poznyak ◽  
Andryy Melnyk
Keyword(s):  
Compressive Strength ◽  
Cementitious Materials ◽  
Cementitious Material ◽  
Supplementary Cementitious Materials ◽  
Polypropylene Fibers ◽  
Supplementary Cementitious Material ◽  
Autoclaved Aerated Concrete ◽  
Aerated Concrete ◽  
The Impact ◽  
Salt Waste

In this paper the impact of carbonate-containing and sulfate components, zeolite, polypropylene fibers on the properties of modified binding composition and non-autoclaved aerated concrete based on them is investigated. The aerated concrete based on the modified binding composition containing a supplementary cementitious material, that of carbonate-containing salt waste, reinforced with polypropylene fibers is characterized by the compressive strength of 2.7 MPa with the density of 650 kg/m3. The thickness of partitions between pores is 0.16 – 0.21 mm, and the number of pores with the size 0.2-1.0 mm is 76.4%.

scholarly journals Static Hardness Testing of Cement Mortars Containing Different Types of Recycled Construction Waste Powders

Solids ◽  
2021 ◽  
Vol 2 (4) ◽  
pp. 331-340
Author(s):  
Zoltán Gyurkó ◽  
Rita Nemes
Keyword(s):  
Compressive Strength ◽  
Indentation Test ◽  
Hardness Test ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Test Results ◽  
Depth Sensing ◽  
Static Hardness ◽  
Cement Mortars ◽  
Aerated Concrete

The present paper deals with the hardness of cement mortars prepared with recycled materials that are potential supplementary cementitious materials (SCM). Two potential SCMs (aerated concrete powder (ACP) and concrete powder) were investigated and compared with a reference (neat cement) sample and a sample containing metakaolin (MK). The long-term performance of the mortars was studied up to the age of one year. Based on the compressive strength tests at different ages, neither concrete powder nor ACP significantly decreases the compressive strength at a 10% substitution ratio. The samples were studied with two types of static hardness tests: the Brinell hardness test and the depth sensing indentation test at two different load levels. The hardness test results indicated that the standard deviation of the results is lower at a higher load level. In the case of metakaolin and concrete powder, the change in the compressive strength was observable in the hardness test results. However, in case of the ACP, the compressive strength decreased, while the hardness increased, which can be traced back to the filler effect of aerated concrete powder. Finally, using the DSI test, the hardness results were analyzed on an energy basis. The analysis highlighted that the change in the hardness is connected to the elastic indentation energy, while it is independent from the dissipated (plastic) indentation energy.

scholarly journals Utilization of Construction and Demolition Waste Along with Fly Ash waste in Preparing Non-Autoclaved Aerated Concrete

2020 ◽  
Vol 5 (3) ◽  
pp. 103-109
Author(s):  
Qunshan Wei ◽  
◽  
Kashif Ali Panhwar ◽  
Zuhair Nadeem ◽  
Kai Zhang ◽  
...  
Keyword(s):  
Fly Ash ◽  
Building Materials ◽  
Lightweight Concrete ◽  
Raw Materials ◽  
Low Cost ◽  
Thermal Power ◽  
Construction And Demolition Waste ◽  
Demolition Waste ◽  
Autoclaved Aerated Concrete ◽  
Aerated Concrete

China’s construction industries are rapidly increasing, and with that generation of Construction and Demolition waste is also growing, and another side industrial waste such as fly ash produced by a thermal power plant, Associated environmental issues, it is essential to utilize in any form; Studies by concrete experts have indicated the feasibility of suitably handling and recycling such waste in new concrete, mainly for basic-level applications. Non-autoclaved aerated concrete is a lightweight substance that could be used as substitute building materials; it is generally made up of raw materials such as Cement, quicklime, gypsum, sand, and expansion agent like an aluminum powder; in this study, 40% waste utilized, Construction and demolition waste (5%,10%,15%,20% ………40%) and Fly ash (35%,30%,25%,20%......0%) accordingly, while expansion agent maintained constant at 0.06%. The compressive strength of the final material checked after (7,14,21 and 28 days) respectively, obtained maximum strength after 28 days; this study goals to design a low cost, Non-autoclaved aerated concrete material and to reuse the waste produced from different sectors, mainly from the construction sector Keywords: Non-Autoclaved concrete, Lightweight concrete, Eco-friendly, Construction and Demolition waste, Fly ash

scholarly journals Effect of Carbonation on Long-Term Measurements of Sorption Isotherms of Autoclaved Aerated Concrete

2015 ◽  
Vol 1126 ◽  
pp. 81-86
Author(s):  
Olga Koronthalyova ◽  
Ľubomír Bagel
Keyword(s):  
Bulk Density ◽  
Water Vapour ◽  
Cementitious Materials ◽  
Density Increase ◽  
Water Vapour Sorption ◽  
Moisture Contents ◽  
Autoclaved Aerated Concrete ◽  
Vapour Sorption ◽  
Aerated Concrete

The laboratory measurement of water vapour adsorption/desorption curves is a standard tool for determination of the moisture capacity of porous building materials in hygroscopic region. However, in case of cementitious materials, additional processes like carbonation can occur during the measurement. Generally, process of carbonation affects the pore structure of the material and results in an increase of its bulk density. Therefore, for determination of correct sorption curves the carbonation caused bulk density increase has to be eliminated. In this work the both mentioned effects of carbonation on the measured water vapour sorption isotherm were quantified for autoclaved aerated concrete (AAC). Within the monitored 9-year period, the carbonation caused noticeable changes in microstructure of the tested AAC samples, namely a decrease of the specific surface area of pores and the portion of very small pores. These microstructure changes affected the moisture storage capacity too – the obtained equilibrium moisture contents of the partly carbonated AAC were lower than the ones of the AAC close to the original state. It was also confirmed that in case of continuous measurement of the water vapour sorption curve the carbonation induced bulk density increase could result in an overestimation of the equilibrium moisture contents.

scholarly journals Concretes with binary mixtures of artificial pozzolans and concrete demolition waste

2020 ◽  
Vol 20 (4) ◽  
pp. 177-188
Author(s):  
Cristian Jonathan Franco de Lima ◽  
Francisco Roger Carneiro Ribeiro ◽  
Geraldo Cechella Isaia ◽  
Mauricio Mancio
Keyword(s):  
Binary Mixtures ◽  
Modulus Of Elasticity ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Demolition Waste ◽  
Durability Test ◽  
Concrete Mixtures ◽  
Pozzolanic Materials

Abstract The objective of this study is to analyse the use of binary mixtures of pozzolanic materials and concrete demolition waste in concrete mixtures, especially the resulting mechanical properties and durability. A total of ten concrete formulations were produced distinguishing them in different types using different Portland cements, different artificial pozzolans and coarse aggregates from concrete demolition. The particular properties of each formulation were verified by testing the axial compressive strength, longitudinal modulus of elasticity and penetration of chloride under immersion. Substitutions were of 15% w.t. and 30% w.t. natural coarse aggregate substituted with concrete demolition waste and, in the case of binary mixtures, additional 25% w.t. of the binder agglomerate substituted with rice husk ash or fly ash. Results showed that the final strength to axial compression and modulus of elasticity of concrete mixtures were negatively affected by utilising demolition waste, but this effect was balanced by adding supplementary cementitious materials. Regarding the durability test, it was found that the lowest coefficients occurred in the mixtures using CP V-ARI, together with artificial pozzolans, in mixtures with 15% w.t. substitution of natural aggregate with recycled aggregate. It was concluded that using recycled aggregates in concrete is viable but conditioned to the concomitant use of pozzolanic materials.

Effect of ground granulated blast funrnace slag and fly ash on strength, permeability, and under-water abrasion of fine-grained concrete

2020 ◽  
Vol 71 (7) ◽  
pp. 775-788
Author(s):  
Quyet Truong Van ◽  
Sang Nguyen Thanh
Keyword(s):  
Fly Ash ◽  
Concrete Strength ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Chloride Permeability ◽  
Cement Replacement ◽  
Fine Grained ◽  
Granulated Blast Furnace Slag ◽  
Compressive Strength Test ◽  
Economic Ground

The utilisation of supplementary cementitious materials (SCMs) is widespread in the concrete industry because of the performance benefits and economic. Ground granulated blast furnace slag (GGBFS) and fly ash (FA) have been used as the SCMs in concrete for reducing the weight of cement and improving durability properties. In this study, GGBFS at different cement replacement ratios of 0%, 20%, 40% and 60% by weight were used in fine-grained concrete. The ternary binders containing GGBFS and FA at cement replacement ratio of 60% by weight have also evaluated. Flexural and compressive strength test, rapid chloride permeability test and under-water abrasion test were performed. Experimental results show that the increase in concrete strength with GGBFS contents from 20% to 40% but at a higher period of maturity (56 days and more). The chloride permeability the under-water abrasion reduced with the increasing cement replacement by GGBFS or a combination of GGBFS and FA

Sign in / Sign up

Export Citation Format

Share Document