scholarly journals The Use of Volcanic Powder as a Cement Replacement for the Development of Sustainable Mortars

2020 ◽  
Vol 10 (4) ◽  
pp. 1460
Author(s):  
Viviana Letelier ◽  
José Marcos Ortega ◽  
Rosa María Tremiño ◽  
Bastián I. Henriquéz-Jara ◽  
Ivo Fustos ◽  
...  
Keyword(s):  
Portland Cement ◽  
Greenhouse Gases ◽  
Pore Structure ◽  
Co2 Emissions ◽  
Environmental Effects ◽  
Ordinary Portland Cement ◽  
Mechanical Performance ◽  
Cement Industry ◽  
Environmental Benefits ◽  
Greenhouse Gases Emissions

Currently, reduction of environmental effects of the cement industry is an issue of global interest and one of the alternatives is to replace clinker with additions such as volcanic powder. The purpose of this work is to study the influence of up to 400 hardening days of volcanic powder, obtained from the last eruption of the Calbuco volcano (Chile), on the pore structure, mechanical performance, and durability-related properties of mortars which incorporate up to 20% volcanic powder as a substitution for clinker. In addition, an evaluation of greenhouse gases emissions was performed in order to quantify the possible environmental benefits of incorporating the volcanic powder in the mortars. The results obtained indicated that mortars with contents of 10% and 20% of volcanic powder had adequate service properties and improved all durability-related properties overall as compared with those noted for ordinary Portland cement. Additionally, the use of up to 20% volcanic powder makes it possible to reduce the CO2 emissions of mortars by almost 20%, demonstrating the advantages of incorporating this addition in mortars.

Utilization of petroleum sludge wastes for increasing productivity of ordinary portland cement

2021 ◽  
Vol 19 (4) ◽  
pp. 315-328
Author(s):  
N.M. Khalil ◽  
Yousif Algamal
Keyword(s):  
Portland Cement ◽  
Ordinary Portland Cement ◽  
Production Capacity ◽  
Hydration Product ◽  
High Energy ◽  
Cement Industry ◽  
Blended Cements ◽  
Petroleum Waste ◽  
Waste Sludge ◽  
Suitable Amount

This work aims at maximum exploitation of petroleum waste sludge as additive to portland cement to prepare blended cements and hence increasing its production capacity without further firing. This will decrease the main cement industry problems involving environmental pollution such as releasing gases and high-energy consumption during industry and hence maximizes the production economics. Six batches of ordinary portland cement (OPC) mixed with different proportions of petroleum waste sludge (PWS) donated as C1 (control batch contains no PWS), C2 (contains 90 wt.% of OPC+10 wt.% of PWS), C3 (contains 80 wt.% of OPC+20 wt.% of PWS), C4 (contains 70 wt.% of OPC+30 wt.% of PWS), C4 (contains 60 wt.% of OPC+40 wt.% of PWS) and C6 (contains 50 wt.% of OPC+50 wt.% of PWS), were prepared and mixed individually with the suitable amount of mixing water. Cement mixes C2, C3 and C4 showed improved cementing and physicomechanical properties compared with pure cement (C1) with special concern of mix C4. Such improvement is due to the relatively higher surface area as well as the high content of kaolinite and quartz in the added PWS (high pozzalanity) favoring the hydration process evidenced by the increase in the cement hydration product (portlandite mineral (Ca (OH) 2).

scholarly journals Development of Eco-Concrete Produced with Calcined Marl Clay as Cement Replacement Material

2021 ◽  
Vol 21 (4) ◽  
pp. 129-137
Author(s):  
Young-Min Kim ◽  
Ji-Su Kim ◽  
Tong-Seok Han
Keyword(s):  
Portland Cement ◽  
Co2 Emissions ◽  
Co2 Emission ◽  
Ordinary Portland Cement ◽  
Chemical Resistance ◽  
Raw Materials ◽  
Performance Difference ◽  
Test Results ◽  
Replacement Ratio ◽  
Cement Replacement

Because of the increase in greenhouse gas emissions and the enforcement of environmental regulations, efforts to reduce CO2 emissions continue. In this study, calcined marl clay was used as a cement replacement material to minimize CO2 emissions by reducing the cement amount used. The raw materials for marl clay were analyzed, and the durability and chemical resistance of concrete produced with marl clay were examined. From the test results, the optimum replacement ratio of calcined marl clay was determined, and the performance difference with ordinary Portland cement (OPC) concrete was identified. The performance of the eco-concrete was comparable to that of the OPC concrete containing marl clay when the cement was optimally replaced with marl clay. Furthermore, the CO2 emission for each specimen was calculated. This study demonstrated the feasibility of developing eco-friendly concrete using calcined marl clay.

scholarly journals Binders alternative to Portland cement and waste management for sustainable construction—part 1

2018 ◽  
Vol 16 (3) ◽  
pp. 186-202 ◽  
Author(s):  
Luigi Coppola ◽  
Tiziano Bellezze ◽  
Alberto Belli ◽  
Maria Chiara Bignozzi ◽  
Fabio Bolzoni ◽  
...  
Keyword(s):  
Waste Management ◽  
Portland Cement ◽  
Greenhouse Gases ◽  
Renewable Resources ◽  
State Of The Art ◽  
Construction Materials ◽  
Sustainable Construction ◽  
Greenhouse Gases Emissions ◽  
Concrete Production ◽  
Alkali Activated

This review presents “a state of the art” report on sustainability in construction materials. The authors propose different solutions to make the concrete industry more environmentally friendly in order to reduce greenhouse gases emissions and consumption of non-renewable resources. Part 1—the present paper—focuses on the use of binders alternative to Portland cement, including sulfoaluminate cements, alkali-activated materials, and geopolymers. Part 2 will be dedicated to traditional Portland-free binders and waste management and recycling in mortar and concrete production.

scholarly journals Alkali-Activated Hybrid Cements Based on Fly Ash and Construction and Demolition Wastes Using Sodium Sulfate and Sodium Carbonate

Molecules ◽  
2021 ◽  
Vol 26 (24) ◽  
pp. 7572
Author(s):  
William Valencia-Saavedra ◽  
Rafael Robayo-Salazar ◽  
Ruby Mejía de Gutiérrez
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Portland Cement ◽  
Sodium Carbonate ◽  
Sodium Sulfate ◽  
Room Temperature ◽  
Ordinary Portland Cement ◽  
Mechanical Performance ◽  
Construction And Demolition Wastes ◽  
Alkali Activated

This article demonstrates the possibility of producing alkali-activated hybrid cements based on fly ash (FA), and construction and demolition wastes (concrete waste, COW; ceramic waste, CEW; and masonry waste, MAW) using sodium sulfate (Na2SO4) (2–6%) and sodium carbonate (Na2CO3) (5–10%) as activators. From a mixture of COW, CEW, and MAW in equal proportions (33.33%), a new precursor called CDW was generated. The precursors were mixed with ordinary Portland cement (OPC) (10–30%). Curing of the materials was performed at room temperature (25 °C). The hybrid cements activated with Na2SO4 reached compressive strengths of up to 31 MPa at 28 days of curing, and the hybrid cements activated with Na2CO3 yielded compressive strengths of up to 22 MPa. Based on their mechanical performance, the optimal mixtures were selected: FA/30OPC-4%Na2SO4, CDW/30OPC-4%Na2SO4, FA/30OPC-10%Na2CO3, and CDW/30OPC-10%Na2CO3. At prolonged ages (180 days), these mixtures reached compressive strength values similar to those reported for pastes based on 100% OPC. A notable advantage is the reduction of the heat of the reaction, which can be reduced by up to 10 times relative to that reported for the hydration of Portland cement. These results show the feasibility of manufacturing alkaline-activated hybrid cements using alternative activators with a lower environmental impact.

scholarly journals Utilization of Iron Ore Tailings as Raw Material for Portland Cement Clinker Production

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Li Luo ◽  
Yimin Zhang ◽  
Shenxu Bao ◽  
Tiejun Chen
Keyword(s):  
Portland Cement ◽  
Iron Ore ◽  
Mechanical Performance ◽  
Mineralogical Composition ◽  
Cement Industry ◽  
Raw Material ◽  
Cement Clinker ◽  
Iron Ore Tailings ◽  
Portland Cement Clinker ◽  
Clinker Production

The cement industry has for some time been seeking alternative raw material for the Portland cement clinker production. The aim of this research was to investigate the possibility of utilizing iron ore tailings (IOT) to replace clay as alumina-silicate raw material for the production of Portland cement clinker. For this purpose, two kinds of clinkers were prepared: one was prepared by IOT; the other was prepared by clay as a reference. The reactivity and burnability of raw meal, mineralogical composition and physical properties of clinker, and hydration characteristic of cement were studied by burnability analysis, differential thermal analysis, X-ray diffraction, and hydration analysis. The results showed that the raw meal containing IOT had higher reactivity and burnability than the raw meal containing clay, and the use of IOT did not affect the formation of characteristic mineralogical phases of Portland cement clinker. Furthermore, the physical and mechanical performance of two cement clinkers were similar. In addition, the use of IOT was found to improve the grindability of clinker and lower the hydration heat of Portland cement. These findings suggest that IOT can replace the clay as alumina-silicate raw material for the preparation of Portland cement clinker.

FBC-Ash as a Substitute of Part Material Raw during Production of Portland Cement

2015 ◽  
Vol 1100 ◽  
pp. 11-14
Author(s):  
Marcela Fridrichová ◽  
Radek Magrla ◽  
Dominik Gazdič ◽  
Jana Stachová
Keyword(s):  
Portland Cement ◽  
Co2 Emissions ◽  
Emission Reduction ◽  
Building Materials ◽  
Cement Industry ◽  
Expected Effect ◽  
Reduction Of Co2 ◽  
Partial Compensation

In the last years we have to think about the question of emission reduction. One of the biggest producer of these emission is industry, where the cement industry comes under it. The effort of cement-workers and other manufacturers of building materials is the reduction of harmful oxides in our air, including CO2, which is one of a group of unfavourable oxides.This paper deals with the study possibility of partial compensation limestone by FBC-ash. The expected effect is the reduction of CO2 emissions and saving limestone. Following the previous stage of the research a recipes were designed for Portland clinker burning limestone-based and FBC ash, it was carried out laboratory burning and on produced cements were made basic technological tests.

scholarly journals Influence of Different Alkali Sulfates on the Shrinkage, Hydration, Pore Structure, Fractal Dimension and Microstructure of Low-Heat Portland Cement, Medium-Heat Portland Cement and Ordinary Portland Cement

2021 ◽  
Vol 5 (3) ◽  
pp. 79
Author(s):  
Yang Li ◽  
Hui Zhang ◽  
Minghui Huang ◽  
Haibo Yin ◽  
Ke Jiang ◽  
...  
Keyword(s):  
Fractal Dimension ◽  
Portland Cement ◽  
Pore Structure ◽  
Ordinary Portland Cement ◽  
Autogenous Shrinkage ◽  
Drying Shrinkage ◽  
Crystal Forms ◽  
Pore Structures ◽  
Cement Based Materials ◽  
Mineral Compositions

In cement-based materials, alkalis mainly exist in the form of different alkali sulfates. In this study, the impacts of different alkali sulfates on the shrinkage, hydration, pore structure, fractal dimension and microstructure of low-heat Portland cement (LHPC), medium-heat Portland cement (MHPC) and ordinary Portland cement (OPC) are investigated. The results indicate that alkali sulfates magnify the autogenous shrinkage and drying shrinkage of cement-based materials with different mineral compositions, which are mainly related to different pore structures and hydration processes. LHPC has the lowest shrinkage. Otherwise, the effect of alkali sulfates on the autogenous shrinkage is more profound than that of drying shrinkage. Compared with the pore size distribution, the fractal dimension can better characterize the shrinkage properties of cement-based materials. It is noted that the contribution of K2SO4 (K alkali) to the promotion effect of shrinkage on cement-based materials is more significant than that of Na2SO4 (Na alkali), which cannot be ignored. The microstructure investigation of different cement-based materials by means of nuclear magnetic resonance (NMR), mercury intrusion porosimetry (MIP) and scanning electron microscope (SEM) shows that this effect may be related to the different pore structures, crystal forms and morphologies of hydration products of cement-based materials.

scholarly journals Increasing the Hydraulic Conductivity of Solidified Sewage Sludge for Use as Temporary Landfill Cover

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Xihui Fan ◽  
Wei Zhu ◽  
Yongjin Qian ◽  
Siling Wu ◽  
Shi Shu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Hydraulic Conductivity ◽  
Sewage Sludge ◽  
Portland Cement ◽  
Pore Structure ◽  
Ordinary Portland Cement ◽  
Aggregate Size ◽  
Low Permeability ◽  
Mercury Intrusion ◽  
Landfill Cover

Using sewage sludge as temporary cover for landfills is one of the most effective methods to dispose sludge. The mechanical properties of solidified sludge usually meet the requirements for temporary landfill cover, but its low permeability can cause problems due to formation of perched leachate. This study focused on the effect of solidification and remolding on hydraulic conductivity of sludge and conducted permeability tests on sludge solidified by using either ordinary Portland cement (OPC) or sulphoaluminate cement (SAC). The related pore structure and aggregate size distribution were analyzed later by the mercury intrusion pressure (MIP) method and soil water characteristic cure (SWCC) method. The experiment results show that the hydraulic conductivity of solidified sludge was in the range of 10−7∼10−6 cm/s. When sludge is solidified with an SAC dosage >40% and remolded after curing for 7 days, its hydraulic conductivity increases sufficiently to the order of 10−4 cm/s. The trend for solidified sludge exhibited a power function relation between the logarithmic hydraulic conductivity and the proportion of macropores. Overall, it can be concluded that the increase of hydraulic conductivity is attributed to the development of an aggregate structure, with water being transmitted mainly through the interaggregate pores; therefore, the sludge could be used as temporary landfill cover.

scholarly journals Effects of Red Mud Addition in the Microstructure, Durability and Mechanical Performance of Cement Mortars

2019 ◽  
Vol 9 (5) ◽  
pp. 984 ◽  
Author(s):  
José Ortega ◽  
Marta Cabeza ◽  
Antonio Tenza-Abril ◽  
Teresa Real-Herraiz ◽  
Miguel Climent ◽  
...  
Keyword(s):  
Portland Cement ◽  
Red Mud ◽  
Mechanical Performance ◽  
Network Evolution ◽  
Cement Industry ◽  
Pozzolanic Activity ◽  
Great Effort ◽  
Chloride Ingress ◽  
Cement Mortars ◽  
Cement Based Materials

Recently, there has been a great effort to incorporate industrial waste into cement-based materials to reach a more sustainable cement industry. In this regard, the Bayer process of obtaining alumina from bauxite generates huge amounts of waste called red mud. Few research articles have pointed out the possibility that red mud has pozzolanic activity. In view of that, the objective of this research is to analyse the short-term effects in the pore structure, mechanical performance and durability of mortars which incorporate up to 20% of red mud as a clinker replacement. As a reference, ordinary Portland cement and fly ash Portland cement mortars were also studied. The microstructure was characterised through mercury intrusion porosimetry and non-destructive impedance spectroscopy, which has not previously been used for studying the pore network evolution of red mud cement-based materials. The possible pozzolanic activity of red mud has been checked using differential scanning calorimetry. The non-steady state chloride migration coefficient and the mechanical properties were studied too. According to the results obtained, the addition of red mud entailed a greater microstructure refinement of the mortar, did not worsen the resistance against chloride ingress and reduced the compressive strength compared to control binders.

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