Environmental-Friendly Mortar Produced with Treated and Untreated Coal Wastes as Cement Replacement Materials

Abstract This study aims to examine the influence of untreated coal waste (UCW) and treated coal waste (TCW) as supplementary cementitious materials (SCMs) on the environmental, mechanical, durability, and microstructural characteristics of mortar mixes. UCW preparation procedure consists of sequential steps of crushing and grinding. Afterward, UCW is thermally activated through incinerating at 750°C to be promoted to TCW. Experimental work includes mixing mortar mixtures by partially replacing cement with the coal waste binders (UCW and TCW) at different incorporation levels of 4, 8, 12, and 16% of cement weight. Toxicity characteristic leaching procedure (TCLP) test was applied to investigate the environmental impacts of coal wastes. TCLP test results pointed out that heavy metals including Manganese, Cadmium, Lead, and Chromium could successfully entrap in the cement matrix. The compressive and flexural strengths as mechanical characteristics of mortar mixtures were determined at 3, 7, 28, 90, and 180 curing days. Moreover, the mortar specimens were immersed in 3% sulfuric acid (H2SO4) for 60 and 150 days. Durability results showed that the H2SO4 attack resistance of binary cement mortars containing 4% coal waste binders was better than the plain mortar. Based on the scanning electron microscopy (SEM) images, ettringite was found as the main hydration product of binary cement after 28 days; however, the existence of calcium silicate hydrate (CSH) and calcium hydroxide (Ca(OH)2) in the cement matrix of mixes after 90 days explains the more compact microstructure attained by using coal waste as cement replacement materials compared to control mixtures.

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

Transport and Communication Science Journal ◽

10.25073/tcsj.71.7.4 ◽

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

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Sustainable low-carbon binders and concretes

E3S Web of Conferences ◽

10.1051/e3sconf/202016606007 ◽

2020 ◽

Vol 166 ◽

pp. 06007

Author(s):

Myroslav Sanytsky ◽

Tetiana Kropyvnytska ◽

Stanislav Fic ◽

Hanna Ivashchyshyn

Keyword(s):

Activity Index ◽

Chemical Properties ◽

High Volume ◽

Cementitious Materials ◽

Supplementary Cementitious Materials ◽

Cement Matrix ◽

Low Carbon ◽

Blended Cements ◽

Physical And Chemical

Sustainable development depends on a consistency of interests, social, ecological and economic, and that the interests are evaluated in a balanced manner. In order to reduce CO2 emissions, the conception of decreasing clinker factor and increasing the role of supplementary cementitious materials (SCMs) in the cementitious materials has high economical and environmental efficiency. The performance of clinkerefficient blended cements with supplementary cementitious materials were examined. The influence of superfine zeolite with increased surface energy on the physical and chemical properties of low-carbon blended cements is shown. Increasing the dispersion of cementitious materials contributes to the growth of their strength activity index due to compaction of cement matrix and pozzolanic reactions in unclincker part. In consequence of the early structure formation and the directed formation of the microstructure of the cement matrix is solving the problem of obtaining clinker-efficient concretes. Shown that low-carbon blended cements with high volume of SCMs are suitable, in principle, for producing structural concretes.

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Modified Plasters for Restoration and Finishing Works

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.923.42 ◽

2014 ◽

Vol 923 ◽

pp. 42-47 ◽

Cited By ~ 11

Author(s):

Myroslav Sanytsky ◽

Tetiana Kropyvnytska ◽

Roman Kotiv

Keyword(s):

Compressive Strength ◽

Chemical Composition ◽

Cementitious Materials ◽

Quality Parameters ◽

Supplementary Cementitious Materials ◽

Cement Matrix ◽

Hydration Products ◽

High Quality ◽

Physico Chemical ◽

White Portland Cement

The paper is devoted to the research and development of modified plasters for restoration and finishing works based on decorative multicomponent cements containing white Portland cement and supplementary cementitious materials (silica fume, metakaolin and fine ground limestone). This cements are similar to Roman cement by their chemical composition. The use of optimal granulometry of decorative multicomponent cements provide directed formation of microstructure of the cement matrix with the formation of stable hydration products. Compositions of modified plasters by the criterions of workability and compressive strength were designed. Physico-chemical modification of plaster by complex air-entraining admixture allows to obtain high-quality modified plasters with improved quality parameters.

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Xonotlite and Hillebrandite as Model Compounds for Calcium Silicate Hydrate Seeding in Cementitious Materials

Transportation Research Record Journal of the Transportation Research Board ◽

10.1177/0361198120943205 ◽

2020 ◽

pp. 036119812094320

Author(s):

Elisabeth John ◽

Christian Lehmann ◽

Dietmar Stephan

Keyword(s):

Calcium Silicate ◽

Calcium Silicate Hydrate ◽

Model Compound ◽

Hydration Product ◽

Cementitious Materials ◽

Nucleation Site ◽

Hydration Products ◽

Sem Images ◽

Pit Formation ◽

Nanoparticle Additives

The demand for more environmentally friendly cement with no disadvantages in relation to hydration activity has led to the development of various additives to accelerate cement hydration. As calcium silicate hydrate (C-S-H) is the major hydration product of cement and is responsible for its mechanical properties, it plays an outstanding role in the discussion of nanoparticle additives. Nevertheless, the investigation of its mechanism of action is complicated by the similarity of its properties to those of the C-S-H that forms as an initial hydration product. Crystalline C-S-H phases, on the other hand, can be easily distinguished from the original hydration products, which makes them a valuable model compound for studying the mechanisms of nucleation seeding in cementitious materials. In this paper, the effect of crystalline types of C-S-H as nucleation seeds are presented. Xonotlite and hillebrandite were thoroughly characterized using nuclear magnetic resonance, X-ray diffractometry (XRD), scanning electron microscopy (SEM), and infrared spectroscopy (IR) and were then used as an admixture for alite pastes. Low-vacuum SEM images of the hydrated pastes revealed that xonotlite can significantly promote the visible etch pit formation on C3S clinker particles, which was not found to be true for hillebrandite. Whether the phases act as a nucleation site is assumed to be strongly dependent on the mineralogy: hillebrandite appeared to be heavily overgrown, but xonotlite did not show any hydration products on its surfaces after the same hydration time of up to 24 h. The diverse effect of the minerals was confirmed by the accelerating behavior in isothermal heat flow calorimetry and by XRD.

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Multi-scale study on synergistic effect of cement replacement by metakaolin and typical supplementary cementitious materials on properties of ultra-high performance concrete

Construction and Building Materials ◽

10.1016/j.conbuildmat.2021.125082 ◽

2021 ◽

Vol 307 ◽

pp. 125082

Author(s):

Peimin Zhan ◽

Jing Xu ◽

Juan Wang ◽

Chenhui Jiang

Keyword(s):

Synergistic Effect ◽

High Performance ◽

High Performance Concrete ◽

Cementitious Materials ◽

Supplementary Cementitious Materials ◽

Ultra High Performance Concrete ◽

Cement Replacement ◽

Multi Scale

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Rice Husk Ash as a Cement Replacement in High Strength Sustainable Concrete

Materials Science Forum ◽

10.4028/www.scientific.net/msf.1007.90 ◽

2020 ◽

Vol 1007 ◽

pp. 90-98

Author(s):

Ash Ahmed ◽

Fraser Hyndman ◽

John Kamau ◽

Heni Fitriani

Keyword(s):

Mechanical Properties ◽

Rice Husk ◽

Rice Husk Ash ◽

Construction Material ◽

Cementitious Materials ◽

Supplementary Cementitious Materials ◽

Strength Development ◽

Coal Waste ◽

Environmental Implications ◽

Sustainable Concrete

Cement is the most utilized construction material. The energy-intensive processes that are involved in its production contribute up to 10% of total global CO2 emissions, with potentially adverse environmental implications. It is however possible, that energy and cost efficiency can be achieved by reducing on the amount of clinker, and in its place utilising supplementary cementitious materials (SCMs) or pozzolans that require less process heating and emit fewer levels of CO2. Currently, most sustainable concrete uses either GGBS (slag) or PFA (fly ash) to reduce the quantity of cement used in construction and highways applications. GGBS and PFA come from industries (steel and coal waste respectively) which are in decline that should not be relied upon in the long term. This report shows that cement in concrete can also be replaced with rice husk ash (RHA) which actually enhances the mechanical properties. RHA comes from the food production industry and is vital for the growing global population. It is thus a socially responsible objective to use a pozzolan in civil engineering applications that is sourced from an environmentally friendly and sustainable industry. This study investigated the potential of RHA to be used as a SCM by evaluating mechanical properties. Experiments were carried out by supplementing cement in concrete mixes with RHA at up to 10% replacement by mass. Results were compared with a control specimen (100% cement), with a water/binder (w/b) ratio of 0.4 and C32/40 design mix using CEM I. The results show excellent early age strengths with all RHA mixes surpassing 40 MPa strength within 7 days which is contrary to general trends in SCM concrete where strength development is slow in the initial stages in comparsion to 100% cement concrete. All RHA specimens exhibited impressive flexural and tensile strengths.

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Effect of MIRHA and Fly Ash in Ductile Self-Compacting Concrete on Abrasion and Impact Performance

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.567.393 ◽

2014 ◽

Vol 567 ◽

pp. 393-398 ◽

Cited By ~ 1

Author(s):

Muhd Fadhil Nuruddin ◽

Norzaireen Mohd Azmee ◽

Kok Yung Chang

Keyword(s):

Fly Ash ◽

Impact Resistance ◽

Cementitious Materials ◽

Supplementary Cementitious Materials ◽

Impact Performance ◽

Cement Replacement ◽

Positive Effects ◽

Partial Cement Replacement ◽

Reference Specimens ◽

The Cost

The benefits of Microwave Incinerated Rice Husk Ash (MIRHA) as partial cement replacement materials in DSCC mixes has led to the research on the possibilities of combining both MIRHA and fly ash as an addition in DSCC replacing up to 20% of cement volume whilst maintaining satisfactory properties. The addition of both materials can improve concrete properties and reduce the cost of DSCC production. These supplementary cementitious materials are expected to give positive effects on the concrete abrasion and impact resistance. The incorporations of both MIRHA and fly ash in DSCC as cement replacement materials are considered as a new type of concrete. Therefore, it is important to have a complete knowledge on the behaviour of the composite material when being subjected to repetitive dynamic loading. The test results showed that MIRHA and fly ash combination in DSCC improved both abrasion and impact resistance of DSCC compared to reference specimens.

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Agricultural Solid Waste as Source of Supplementary Cementitious Materials in Developing Countries

Materials ◽

10.3390/ma12071112 ◽

2019 ◽

Vol 12 (7) ◽

pp. 1112 ◽

Cited By ~ 14

Author(s):

Suvash Chandra Paul ◽

Peter Mbewe ◽

Sih Kong ◽

Branko Šavija

Keyword(s):

Developing Countries ◽

Cementitious Materials ◽

Agricultural Wastes ◽

Cement Industry ◽

Supplementary Cementitious Materials ◽

Engineering Properties ◽

Partial Replacement ◽

Cement Production ◽

Cement Replacement ◽

Concrete Production

Concrete production utilizes cement as its major ingredient. Cement production is an important consumer of natural resources and energy. Furthermore, the cement industry is a significant CO2 producer. To reduce the environmental impact of concrete production, supplementary cementitious materials such as fly ash, blast furnace slag, and silica fume are commonly used as (partial) cement replacement materials. However, these materials are industrial by-products and their availability is expected to decrease in the future due to, e.g., closing of coal power plants. In addition, these materials are not available everywhere, for example, in developing countries. In these countries, industrial and agricultural wastes with pozzolanic behavior offer opportunities for use in concrete production. This paper summarizes the engineering properties of concrete produced using widespread agricultural wastes such as palm oil fuel ash, rice husk ash, sugarcane bagasse ash, and bamboo leaf ash. Research on cement replacement containing agricultural wastes has shown that there is great potential for their utilization as partial replacement for cement and aggregates in concrete production. When properly designed, concretes containing these wastes have similar or slightly better mechanical and durability properties compared to ordinary Portland cement (OPC) concrete. Thus, successful use of these wastes in concrete offers novel sustainable materials and contributes to greener construction as it reduces the amount of waste, while also minimizing the use of virgin raw materials for cement production. This paper will help the concrete industry choose relevant waste products and their optimum content for concrete production. Furthermore, this study identifies research gaps which may help researchers in further studying concrete based on agricultural waste materials.

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Assessment of Raw Mineral Waste as Building Materials in Developing Countries

International Journal of Engineering Research in Africa ◽

10.4028/www.scientific.net/jera.40.30 ◽

2018 ◽

Vol 40 ◽

pp. 30-46

Author(s):

Njarazo Rakotondrabezaharinoro ◽

Moutari Ado ◽

Willy Hermann Juimo Tchamdjou

Keyword(s):

Mechanical Properties ◽

Developing Countries ◽

Portland Cement ◽

Building Materials ◽

Raw Materials ◽

Activity Index ◽

Cementitious Materials ◽

Supplementary Cementitious Materials ◽

Cement Replacement ◽

Mineral Waste

In many developing country’s mining exploitations are the main activities sources, and its exploitation is generating many mining wastes and environmental impacts. In order to use these waste, an innovative powder and aggregate were designed, aimed at providing alternative materials by cementitious supplementary materials and sand in Portland cement mortars. This paper investigates the use of raw mineral waste from some developing countries, namely Granite Residue (GR), from Niger, Mining Tailings (MT), from Madagascar, and red Volcanic Scoria (VS), from Cameroon as building materials. These raw materials were valorized as supplementary cementitious materials (GR powder, MS powder and VS powder) and as sand (GR sand and VS sand). GR sand and VS sand were used by 100% replacement of standard sand and GR powder, MS powder and VS powder were used by 5, 15, 25, or/and 35% cement replacement. Physical properties and mechanical properties of raw materials used and mortars obtained were investigated. The effects of these raw materials on properties of mortar mixes were studied and reported. Results show that, with sand from raw mineral waste materials, the compressive and flexural strengths of the produced mortar represented up than 70% and up than 85% respectively in comparison with mortar produce with siliceous standard sand. The reduction of strength of mortar with raw powder as ordinary Portland cement replacement is generally smaller than replacement ratio. Activity index of each raw powder is about 75% for ratio replacement of 5, 15 and 25%. Particle size distribution of raw powder and sand have an influence on the workability and mechanical properties of mortars. In conclusion, the use of raw mineral waste as a raw powder or as sand for mortar production presents an economical and environmental advantage for developing countries where mining exploitations are abundant.

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