scholarly journals CO2 Uptake of Carbonation-Cured Cement Blended with Ground Volcanic Ash

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2187 ◽  
Author(s):  
Joon Seo ◽  
Issam Amr ◽  
Sol Park ◽  
Rami Bamagain ◽  
Bandar Fadhel ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Volcanic Ash ◽  
Blended Cement ◽  
Pozzolanic Reaction ◽  
Partial Replacement ◽  
Co2 Uptake ◽  
Supplementary Cementitious Material ◽  
Natural Minerals ◽  
The Matrix ◽  
Carbonation Curing

Accelerated carbonation curing (ACC) as well as partial replacement of cement with natural minerals are examples of many previous approaches, which aimed to produce cementitious products with better properties and environmental amicabilities. In this regard, the present study investigates CO2 uptake of carbonation-cured cement blended with ground Saudi Arabian volcanic ash (VA). Paste samples with cement replacement of 20%, 30%, 40%, and 50% by mass were prepared and carbonation-cured after initial curing of 24 h. A compressive strength test, X-ray diffractometry (XRD), and thermogravimetry were performed. Although pozzolanic reaction of VA hardly occurred, unlike other pozzolana in blended cement, the results revealed that incorporation of VA as a supplementary cementitious material significantly enhanced the compressive strength and diffusion of CO2 in the matrix. This increased the CO2 uptake capacity of cement, reducing the net CO2 emission upon carbonation curing.

High Volume Slag and Slag-Fly Ash Blended Cement Pastes Containing Nano Silica

2019 ◽  
Vol 967 ◽  
pp. 205-213
Author(s):  
Faiz U.A. Shaikh ◽  
Anwar Hosan
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Cement Paste ◽  
Ordinary Portland Cement ◽  
Blended Cement ◽  
High Volume ◽  
Ash Content ◽  
Partial Replacement ◽  
Nano Silica ◽  
Cement Pastes

This paper presents the effect of nanosilica (NS) on compressive strength and microstructure of cement paste containing high volume slag and high volume slag-fly ash blend as partial replacement of ordinary Portland cement (OPC). Results show that high volume slag (HVS) cement paste containing 60% slag exhibited about 4% higher compressive strength than control cement paste, while the HVS cement paste containing 70% slag maintained the similar compressive strength to control cement paste. However, about 9% and 37% reduction in compressive strength in HVS cement pastes is observed due to use of 80% and 90% slag, respectively. The high volume slag-fly ash (HVSFA) cement pastes containing total slag and fly ash content of 60% exhibited about 5%-16% higher compressive strength than control cement paste. However, significant reduction in compressive strength is observed in higher slag-fly ash blends with increasing in fly ash contents. Results also show that the addition of 1-4% NS improves the compressive strength of HVS cement paste containing 70% slag by about 9-24%. However, at higher slag contents of 80% and 90% this improvement is even higher e.g. 11-29% and 17-41%, respectively. The NS addition also improves the compressive strength by about 1-59% and 5-21% in high volume slag-fly ash cement pastes containing 21% fly ash+49%slag and 24% fly ash+56%slag, respectively. The thermogravimetric analysis (TGA) results confirm the reduction of calcium hydroxide (CH) in HVS/HVSFA pastes containing NS indicating the formation of additional calcium silicate hydrate (CSH) gels in the system. By combining slag, fly ash and NS in high volumes e.g. 70-80%, the carbon footprint of cement paste is reduced by 66-76% while maintains the similar compressive strength of control cement paste. Keywords: high volume slag, nanosilica, compressive strength, TGA, high volume slag-fly ash blend, CO2 emission.

scholarly journals Effect of Different Hydration Time on Carbonation Degree and Strength of Steel Slag Specimens Containing Zeolite

Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3898
Author(s):  
Xiong Zhang ◽  
Jun Chang
Keyword(s):  
Compressive Strength ◽  
Steel Slag ◽  
Pozzolanic Reaction ◽  
Test Methods ◽  
New Mineral ◽  
Curing Time ◽  
Hydration Time ◽  
Carbonation Process ◽  
Substitution Ratio ◽  
Carbonation Curing

Steel slag partially substituted by zeolite (SZ) was beneficial for improving the compressive strength and carbonation degree of SZ specimens after a combined curing (hydration and then carbonation) process due to pozzolanic reaction between them. By previous work results, the zeolitic substitution ratios of 5 wt.% and 15 wt.% in steel slag specimens (SZ5 and SZ15) gained the optimum compressive strength and carbonation degree, respectively, after 1 day hydration and then 2 h carbonation. This study investigated the effect of previous hydration time (1, 3, 7, 14, and 196 days) on carbonation degree and strength of SZ specimens after subsequent carbonation curing. Two zeolitic substitution ratios (5 wt.% and 15 wt.%) were selected and pure steel slag specimens were also prepared as controls. Compressive strength results revealed that the optimum hydration curing time was 1 day and the optimum zeolitic substitution ratio was 5 wt.%. The pozzolanic reaction happened in SZ specimens was divided into early and late pozzolanic reaction. In the late hydration, a new mineral, monocarboaluminate (AFmc) was produced in SZ15 specimens, modifying the carbonation degree and strength further. And the mechanism of pozzolanic reaction in early and late hydration in SZ specimens was explained by several microscopic test methods.

scholarly journals Permeation Resistance of Sawdust Ash Blended Cement Laterized Concrete

2019 ◽  
Vol 21 (2) ◽  
pp. 76-83 ◽  
Author(s):  
Samuel Olufemi Folagbade ◽  
Aluko Olawale
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Blended Cement ◽  
The Other ◽  
Partial Replacement ◽  
Initial Surface ◽  
Surface Absorption ◽  
Conventional Concrete ◽  
Other Hand ◽  
Curing Age

This paper compared the initial surface absorption of conventional concrete and laterized concrete containing Portland cement (PC) and sawdust ash (SDA). Laterized concrete was produced at laterite contents of 15 and 30% as partial replacement for sand and SDA contents of 10 and 20% as partial replacement for PC. Compressive strengths at 28 days and initial surface absorption after 10 minutes (ISA-10) at 28, 60 and 90 days were determined at the water/cement ratios of 0.35, 0.50 and 0.65 and assessed at equal 28-day strengths of 25-35 N/mm2. At equal water/cement ratios, compressive strength reduced and ISA-10 increased with increasing content of laterite and SDA. On the other hand, compressive strength and resistance to surface absorption of the blended cement laterized concretes increased with increasing curing age. At equal strengths, all the blended cement laterized concretes have better resistance to surface absorption than the conventional PC concrete.

The Effect of Micronized Waste Marble Powder as Partial Replacement for Cement on Resulting Mechanical Properties of Cement Pastes

2017 ◽  
Vol 1144 ◽  
pp. 54-58
Author(s):  
Zdeněk Prošek ◽  
Karel Šeps ◽  
Jaroslav Topič
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Reference Material ◽  
Dynamic Modulus ◽  
Blended Cement ◽  
Partial Replacement ◽  
Dynamic Shear Modulus ◽  
Dynamic Shear ◽  
Cement Pastes ◽  
Marble Powder

This article was focused on the influence of the micronized waste marble powder on mechanical properties of cement pastes. Resulting blended cement was composed of Portland cement CEM I 42.5 R and micronized marble powder with different percentage amounts (0 wt. %, 5 wt. %, 10 wt. % and 15 wt. %). Testing was carried at prismatic samples of dimension 40 × 40 × 160 mm. The investigated mechanical properties were dynamic modulus of elasticity, dynamic shear modulus, flexural strength and compressive strength for the 28 days old samples. The results obtained from these materials were compared with reference material.

scholarly journals Effect of Using Micropalm Oil Fuel Ash as Partial Replacement of Cement on the Properties of Cement Mortar

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Kwangwoo Wi ◽  
Han-Seung Lee ◽  
Seungmin Lim ◽  
Mohamed A. Ismail ◽  
Mohd Warid Hussin
Keyword(s):  
Compressive Strength ◽  
Cement Mortar ◽  
Isothermal Calorimetry ◽  
High Surface ◽  
High Surface Area ◽  
Xrd Analysis ◽  
Pozzolanic Reaction ◽  
Partial Replacement ◽  
Fuel Ash ◽  
Oil Fuel

This study investigates the effects of micropalm oil fuel ash (mPOFA) on compressive strength and pore structure of cement mortar. Various experimental techniques, such as compression test, isothermal calorimetry, mercury intrusion porosimetry, and X-ray diffraction, are performed to figure out the effect of using mPOFA as partial replacement of cement on the hydration of cement and determine its optimal replacement level to increase mechanical property of the mortar specimens. 10 wt.% of cement replacement with mPOFA is found to give the highest level of compressive strength, achieving a 23% increase over the control specimens after 3 days of curing. High K2O contents in mPOFA stimulate C3S in cement to form C-S-H at early ages, and high surface area of mPOFA acts as a nucleus to develop C-S-H. Also, small mPOFA particles and C-S-H formed by pozzolanic reaction fill the pores and lead to reduction in large capillary pores. In XRD analysis, a decrease in Ca(OH)2 and SiO2 contents with age confirmed a high pozzolanic reactivity of mPOFA.

Some Difficulties in the Assessment of Pore-Structure of High Performance Blended Cement Pastes

1984 ◽  
Vol 42 ◽  
Author(s):  
Bryan K. Marsh ◽  
Robert L. Day
Keyword(s):  
Pore Structure ◽  
High Performance ◽  
Mercury Porosimetry ◽  
Blended Cement ◽  
High Strength ◽  
Pozzolanic Reaction ◽  
Partial Replacement ◽  
Microstructural Characteristics ◽  
Cement Pastes ◽  
Correct Analysis

AbstractPartial replacement of cement by fly-ash allows the production of concretes with high strength and low permeability. The correct analysis and prediction of engineering behaviour requires a knowledge of the development of pore-structure of these materials. However, a study of the relationships between engineering and microstructural characteristics has revealed problems in the accurate assessment of pore-structure.Porosities of plain and blended pastes were analysed by both helium pycnometry and mercury porosimetry. Pastes showing pozzolanic reaction gave values of helium porosity whidh were different from the mercury porosity (measured on the same sample); pastes showing no pozzolanic reaction gave equal values for mercury and helium porosity. Also, significant differences in porosity and pore-size distribution were found for identical specimens when prepared by different techniques, namely direct oven-drying and solventreplacement; these differences occurred whether there was pozzolanic reaction or not.It is suggested that as well as experimental difficulties, there may be fundamental differences in the way pore-structure develops in plain and blended cement pastes.

scholarly journals Comparative Analysis of Flexural Strength and Modulus Elasticity of Sustainable Concrete Using Supplementary Cementitious Material (SCM)

2020 ◽  
Author(s):  
Shahab Samad ◽  
Attaullah Shah
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Modulus Of Elasticity ◽  
Blended Cement ◽  
Cementitious Material ◽  
Supplementary Cementitious Material ◽  
Curing Conditions ◽  
Blended Cements ◽  
Sustainable Concrete ◽  
Cement Manufacturing

The use of Supplementary Cementitious Material (SCM) is widely used in production of sustainable concrete. Blended cements, incorporating SCM such as Pulverized Fly Ash (PFA) and Ground Granulated Blast Furnace Slag (GGBFS) have been widely used to reduce the cement contents and avoid adverse environmental impacts of CO2 produced during cement manufacturing. The analysis of various structural properties of concrete such as compressive strength, flexural strength and modulus of elasticity is important for its structural application. In this research, flexural strength of 100mmx100mmx500mm beams made from blended cement were tested under three curing conditions i.e. winter, summer and under water and the flexural strength was calculated using EN-12390-5 at the ages of 28 days and 56 days. For modulus of elasticity, concrete cylinders 150mmx300mm were tested as per procedure described in BS 1881-121(1983) at the age of 28 days. The compressive strength, flexural strength and modulus of elasticity for blended cement incorporating PFA and GGBFS has been increased under summer curing environment. The experimental values of Modulus of Elasticity are compared with the provision of BS 1881.

scholarly journals Strength and Workability Assessment of Concrete Produced by Partial Replacement of Cement with Waste Clay Bricks

2019 ◽  
Vol 3 (2) ◽  
pp. 352-360
Author(s):  
Ebuka Nwankwo ◽  
A. T. John
Keyword(s):  
Compressive Strength ◽  
Construction Industry ◽  
Niger Delta ◽  
Partial Replacement ◽  
Clay Brick ◽  
Supplementary Cementitious Material ◽  
Clay Bricks ◽  
Niger Delta Region ◽  
Compressive Strength Of Concrete ◽  
Pozzolanic Properties

The use of waste clay bricks—which are abundant in the Niger Delta Region of Nigeria – as supplementary cementitious material, would enable the construction industry utilize thousands of tons of brick blocks that would have ended up as waste or landfill materials. This paper establishes the pozzolanic properties of these waste clay bricks in terms of strength and workability. Waste clay brick powders are introduced as partial replacement for cement in this research. All tests were done in accordance with relevant British Standards. It was observed that waste clay brick, as an admixture, increases the workability and consistency of fresh concrete. Also, an 11 percent increase in compressive strength was observed with a 10 percent partial replacement of cement with waste clay brick powders. An equation is developed to capture the marginal increase in compressive strength of concrete produced with waste clay bricks, even after 28 days, for a 10% partial replacement of cement.

scholarly journals Eco-efficient concrete, optimized by Alfred’s particle packing model, with partial replacement of Portland cement by stone powder

2022 ◽  
Vol 15 (2) ◽  
Author(s):  
Heloisa Fuganti Campos ◽  
André Lucas Bellon ◽  
Eduardo Reis de Lara e Silva ◽  
Maurício Villatore Junior
Keyword(s):  
Compressive Strength ◽  
Co2 Emissions ◽  
Cementitious Materials ◽  
Particle Packing ◽  
Partial Replacement ◽  
Cement Particle ◽  
Distribution Factor ◽  
Packing Model ◽  
The Matrix ◽  
Hardened State

Abstract The partial replacement of clinker by complementary cementitious materials can significantly contribute to the reduction of carbon emissions in the production of concrete. Another alternative to reduce these emissions is to increase the efficiency of the concrete, achieving higher compressive strength with lower consumption of cement. Particle packing models are efficient tools to optimize the composition of the matrix and contribute to the production of more eco-efficient concretes. In this context, the objective of the present study is evaluating the production of concretes with partial replacement of cement by stone powder, optimized by Alfred’s particle packing model, seeking to reduce cement consumption and CO2 emissions per MPa of compressive strength. The replacement content of cement by stone powder was 20% by mass (equivalent to 22.4% by volume). Concretes were produced with different distribution factor (q) - 0.37; 0.21; 0.45 - to verify the influence of fines on the flow between particles and on the efficiency of the produced concrete. The analyses were carried out in terms of properties in the fresh state, hardened state, and sustainability parameters (cement consumptions and CO2 emissions). The application of the proposed method resulted in a higher compressive strength than the expected for the water/cement ratio used (0.5). The most efficient concrete reached the compressive strength of 68 MPa with 240 kg/m3 of cement, which represents 3.5 kg of cement/m3/MPa and 3.1 kg of CO2/m3/MPa, a value below the references found in the literature for conventional concretes. Therefore, the proposed method allows to produce more eco-efficient concrete, contributing to the use of waste and reducing CO2 emissions.

scholarly journals Physical and Mechanical Properties of a Porous Material Obtained by Low Replacement of Volcanic Ash by Aluminum Beverage Cans

2021 ◽  
pp. 1-11
Author(s):  
Bernard Missota Priso Dickson ◽  
Claudine Mawe Noussi ◽  
Louise Ndongo Ebongue ◽  
Joseph Dika Manga
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Porous Material ◽  
Water Absorption ◽  
Bulk Density ◽  
Volcanic Ash ◽  
Physical And Mechanical Properties ◽  
Apparent Porosity ◽  
Partial Replacement ◽  
Inorganic Polymers

This study focuses on the evaluation of the physical and mechanical properties of a porous material based on a mixture of powder (Volcanic ash /Aluminum Beverage Cans) and a solution of phosphoric acid. Volcanic ash (VA) use was collected in one of the quarries of Mandjo (Cameroon coastal region), crushed, then characterized by XRF, DRX, FTIR and named MaJ. The various polymers obtained are called MaJ0, MaJ2.5, MaJ5, MaJ7.5 and MaJ10 according to the mass content of the additions of the powder from the aluminum beverage cans (ABCs). The physical and mechanical properties of the synthetic products were evaluated by determining the apparent porosity, bulk density, water absorption and compressive strength. The results of this study show that the partial replacement of the powder of VA by that of ABC leads to a reduction in the compressive strength (5.9 - 0.8 MPa) and bulk density (2.56 – 1.32 g/cm3) of the polymers obtained. On the other hand, apparent porosity, water absorption and pore formation within the polymers increases with addition of the powder from the beverage cans. All of these results allow us to agree that the ABCs powder can be used as a blowing agent during the synthesis of phosphate inorganic polymers.

Sign in / Sign up

Export Citation Format

Share Document