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 Unconfined Compressive Strength Characteristics of Overboulder Asbuton and Zeolite Stabilized Soft Soil

2021 ◽  
Vol 7 (1) ◽  
pp. 40-48
Author(s):  
Noor Dhani ◽  
Ahmad Gasruddin ◽  
Hartini Hartini ◽  
La Baride
Keyword(s):  
Compressive Strength ◽  
Soil Stabilization ◽  
Soft Soil ◽  
Pozzolanic Reaction ◽  
Silica Content ◽  
Curing Time ◽  
Natural Pozzolan ◽  
Soil Stabilizer ◽  
Proctor Test ◽  
High Silica

Soft soil was one of the most widely encountered problems in construction, especially for archipelago countries which most of its area was lowland with a high deposit of soft soil. To overcome this problem, soil stabilization was one of the most widely used as a solution. Soil stabilization in general uses chemical substances that are classified as pozzolan material. Pozzolan material uses its capability to strengthen the cohesion of soil grains. Mostly, pozzolan material consists of silica. Overboulder asbuton and zeolite were examples of natural pozzolan material in Indonesia. Both materials have a high silica content. Thus, the author interested to figure out the mechanical behavior of these two substances as a soil stabilizer. This research was a correlating study to the previous paper with the same author which discusses the overboulder asbuton as a soil stabilizer. Overboulder added to the mix is determined as 15%, with varied zeolite percentages applied to examine the differences. The UCT was conducted according to ASTM D-2166 as a parameter. As the standard remolding method, a standard proctor test was conducted to determine the optimum moisture content and the maximum density of each mix. While the UCT specimens were tested at the certain curing time for each composition. The curing time applied was 0, 7, 14, and 28 days. By this curing period, the effective pozzolanic reaction that occurs for each composition could be determined. The result shows that zeolite addition to overboulder asbuton could increase the soil density and increase its compressive strength. It is indicated that overboulder asbuton and zeolite mix could be a proper alternative as a soil stabilizer. Doi: 10.28991/cej-2021-03091635 Full Text: PDF

The Properties of Steel Slag Bricks Prepared by both Alkali Activation and Accelerated Carbonation

2012 ◽  
Vol 509 ◽  
pp. 113-118 ◽  
Author(s):  
Wen Sheng Zhang ◽  
Di Shi ◽  
Zhong Jun Shao ◽  
Jia Yuan Ye ◽  
Yuan Wang
Keyword(s):  
Compressive Strength ◽  
Dominant Role ◽  
Steel Slag ◽  
Alkali Activation ◽  
Accelerated Carbonation ◽  
Mineral Compositions ◽  
Physical And Chemical ◽  
Carbonation Curing

The physical and chemical evolutions, including strength, porosity, chemical and mineral compositions, of properties of steel slag bricks prepared by both alkali activation and accelerated carbonation were investigated. The results show that alkali activation provides the initial properties, while accelerated carbonation plays a dominant role in such final performances as strength, porosity, chemical and mineral compositions of steel slag bricks. The steel slag bricks with a compressive strength of 33.8MPa, carbonation degree of 8.92% and porosity of 23.25% were successfully prepared after accelerated carbonation curing (T=50°C, RH=60%, P=0.25MPa, ρCO2=80% by volume) for 120min.

scholarly journals Development of a New Ecological Material Based on Moroccan Industrial Wastes for Road Construction

2020 ◽  
Author(s):  
Achraf Harrou ◽  
El Khadir Gharibi ◽  
Yassine Taha ◽  
Nathalie Fagel ◽  
Meriam El Ouahabi
Keyword(s):  
Compressive Strength ◽  
Steel Slag ◽  
Road Construction ◽  
Pozzolanic Reaction ◽  
Industrial Wastes ◽  
X Ray Diffraction ◽  
Hydration Kinetics ◽  
Hydrated Calcium Silicate ◽  
Pozzolanic Reactivity ◽  
Kinetics Of

The Black Steel slag (Ss) and phosphogypsum (PG) are industrial wastes produced in Morocco. In order to reduce these two wastes and to evaluate their pozzolanic reactivity in the presence of water, they were incorporated into bentonite (B) mixed with lime (L). The studied mixtures (BLW, BL-PG-W and BL-PG-Ss-W) were analyzed by X-ray diffraction, Infrared spectroscopy, Raman spectroscopy and SEM/EDX analysis. Compressive strength tests were performed on hardened specimens. The results obtained show that the hydration kinetics of the B-L-W and B-L-PG-W mixtures are slow. The addition of PG to a bentonite-lime mixture induces the formation of new microstructures such as hydrated calcium silicate (C-S-H) and ettringite, which increases the compressive strength of the cementitious specimens. The addition of the Ss to a mixture composed by 8%PG and 8%L-B accelerates the kinetics of hydration and activates the pozzolanic reaction. The presence of C2S in the slag helps to increase the mechanical strength of the mixture B-L-PG-Ss. The compressive strength of the mixtures BL-W, BL-PG-W and BL-PG-Ss-W increases from 15 to 28 days of setting. After 28 days of setting, 8% of Sc added to the mixture 8% PG-8%L-B is responsible for an increase of the compressive strength to 0.6 MPa.

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.

scholarly journals Solidification/Stabilization of Fly Ash from a Municipal Solid Waste Incineration Facility Using Portland Cement

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Qiang Tang ◽  
Yang Liu ◽  
Fan Gu ◽  
Ting Zhou
Keyword(s):  
Heavy Metals ◽  
Compressive Strength ◽  
Fly Ash ◽  
Portland Cement ◽  
Metal Ion ◽  
Waste Incineration ◽  
Pozzolanic Reaction ◽  
Strength Ratio ◽  
Curing Time ◽  
Ion Migration

This study investigated the solidification/stabilization of fly ash containing heavy metals using the Portland cement as a binder. It is found that both the cement/fly ash ratio and curing time have significant effects on the mechanical (i.e., compressive strength) and leaching behaviors of the stabilized fly ash mixtures. When the cement/fly ash ratio increases from 4 : 6 to 8 : 2, the increase of compressive strength ratio raises from 42.24% to 80.36%; meanwhile, the leaching amount of heavy metals decreases by 2.33% to 85.23%. When the curing time increases from 3 days to 56 days, the compressive strength ratio of mixtures raises from 240.00% to 414.29%; meanwhile, the leaching amount of heavy metals decreases by 16.49% to 88.70%. The decrease of compressive strength with the lower cement/fly ash ratios and less curing time can be attributed to the increase of fly ash loading, which hinders the formation of ettringite and destroys the structure of hydration products, thereby resulting in the pozzolanic reaction and fixation of water molecules. Furthermore, the presence of cement causes the decrease of leaching, which results from the formation of ettringite and the restriction of heavy metal ion migration in many forms, such as C-S-H gel and adsorption.

Exploration for the Technology of Tradition Building Materials and Consolidation Mechanism

2014 ◽  
Vol 548-549 ◽  
pp. 1689-1695 ◽  
Author(s):  
Min Dai ◽  
Chang Sheng Peng ◽  
Wei Zheng ◽  
Jia Lai Wang ◽  
Xin Qian
Keyword(s):  
Compressive Strength ◽  
Building Materials ◽  
Pozzolanic Reaction ◽  
Molding Pressure ◽  
Strength Development ◽  
Historical Records ◽  
Curing Time ◽  
Curing Method ◽  
Increasing Temperature ◽  
Main Factor

In this paper, we exploded the technology of Sanhetu based on the historical records and previous studies. Mixing technology, molding pressure, W/S, curing time and curing method were investigated to increase the compressive strength of the imitating samples. XRD, FTIR and SEM were used to analyze the composition and consolidation mechanism. The results show that the compressive strength of the imitation could exceed 50 MPa, when molding pressure is 20 MPa, W/S is 0.49 with mixing technology A. Pozzolanic reaction is significant in strength development. And the reaction product, CSH gel, is the main factor in strength gain. Sufficient inner water of the imitating samples could contribute to the pozzolanic reaction. And increasing temperature could accelerate the reaction. The study confirms the possibility of the imitation for Sanhetu.

Microstructure, Mineral Phases and Strength of the Foam Concrete

2011 ◽  
Vol 492 ◽  
pp. 484-488 ◽  
Author(s):  
Xin Gang Yu ◽  
Shi Song Luo ◽  
Yan Na Gao ◽  
Huaan Xiao ◽  
De Jun Li ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Steel Slag ◽  
Curing Time ◽  
Foam Concrete ◽  
Strength Of Materials ◽  
Mineral Phases ◽  
Materials Research ◽  
The Relationship

The relationship among the composition, microstructure and strength of materials is always one of the hotspots for scholars of materials research. The influence of curing time on the compressive strength and flexural strength of the foam concrete with the cement, cement-slag and cement-steel slag as main binder respectively was studied in this paper. The microstructure of these foam concrete was analyzed by SEM and the mineral phases of the foam concrete was analyzed by XRD. The relationship among the binders, microstructure, mineral phases and strength of the foam concrete were explored and the reasons of why the strength of the cement foam concrete and cement-slag foam concrete is much higher than that of the cement-steel slag foam concrete are proposed.

scholarly journals Phosphogypsum and Black Steel Slag as Additives for Ecological Bentonite-Based Materials: Microstructure and Characterization

Minerals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1067
Author(s):  
Achraf Harrou ◽  
El Khadir Gharibi ◽  
Yassine Taha ◽  
Nathalie Fagel ◽  
Meriam El Ouahabi
Keyword(s):  
Compressive Strength ◽  
Steel Slag ◽  
Pozzolanic Reaction ◽  
Industrial Wastes ◽  
X Ray Diffraction ◽  
Hydration Kinetics ◽  
Hydrated Calcium Silicate ◽  
Pozzolanic Reactivity ◽  
Strength Tests ◽  
Kinetics Of

The Black Steel slag (Ss) and phosphogypsum (PG) are industrial wastes produced in Morocco. In order to reduce these two wastes and to evaluate their pozzolanic reactivity in the presence of water, they were incorporated into bentonite (B) mixed with lime (L). The studied mixtures (BLW, BL–PG–W and BL–PG–Ss–W) were analyzed by X-ray diffraction, Infrared spectroscopy, Raman spectroscopy and SEM/EDX analysis. Compressive strength tests were performed on hardened specimens. The results obtained show that the hydration kinetics of the B–L–W and B–L–PG–W mixtures are slow. The addition of PG to a bentonite––lime mixture induces the formation of new microstructures such as hydrated calcium silicate (C–S–H) and ettringite, which increases the compressive strength of the cementitious specimens. The addition of the Ss to a mixture composed of 8%PG and 8%L–B accelerates the kinetics of hydration and activates the pozzolanic reaction. The presence of C2S in the slag helps to increase the mechanical strength of the mixture B–L–PG–Ss. The compressive strength of the mixtures BL–W, BL–PG–W and BL–PG–Ss–W increases from 15 to 28 days of setting. After 28 days of setting, 8% of Sc added to the mixture 8% PG–8%L–B is responsible for an increase of the compressive strength to 0.6 MPa.

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