scholarly journals Utilization of Solid Waste from Brick Industry and Hydrated Lime in Self-Compacting Cement Pastes

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1109
Author(s):  
Mati Ullah Shah ◽  
Muhammad Usman ◽  
Muhammad Usman Hanif ◽  
Iqra Naseem ◽  
Sara Farooq
Keyword(s):  
Mechanical Properties ◽  
Solid Waste ◽  
Manufacturing Industry ◽  
Setting Time ◽  
Hydrated Lime ◽  
Pozzolanic Reaction ◽  
Early Age ◽  
Cement Pastes ◽  
Brick Powder ◽  
High Degree

The huge amount of solid waste from the brick manufacturing industry can be used as a cement replacement. However, replacement exceeding 10% causes a reduction in strength due to the slowing of the pozzolanic reaction. Therefore, in this study, the pozzolanic potential of brick waste is enhanced using ultrafine brick powder with hydrated lime (HL). A total of six self-compacting paste mixes were studied. HL 2.5% by weight of binder was added in two formulations: 10% and 20% of waste burnt brick powder (WBBP), to activate the pozzolanic reaction. An increase in the water demand and setting time was observed by increasing the replacement percentage of WBBP. It was found that the mechanical properties of mixes containing 5% and 10% WBBP performed better than the control mix, while the mechanical properties of the mixes containing 20% WBBP were found to be almost equal to the control mix at 90 days. The addition of HL enhanced the early-age strength. Furthermore, WBBP formulations endorsed improvements in both durability and rheological properties, complemented by reduced early-age shrinkage. Overall, it was found that brick waste in ultrafine size has a very high degree of pozzolanic potential and can be effectively utilized as a supplementary cementitious material.

scholarly journals Nano-TiO2 in Hydraulic Lime–Metakaolin Mortars for Restoration Projects: Physicochemical and Mechanical Assessment

Buildings ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 236
Author(s):  
Kali Kapetanaki ◽  
Chrysi Kapridaki ◽  
Pagona-Noni Maravelaki
Keyword(s):  
Mechanical Properties ◽  
Setting Time ◽  
Hydrated Lime ◽  
Pozzolanic Reaction ◽  
Plastic Behavior ◽  
Hydraulic Lime ◽  
Three Point Bending ◽  
Natural Pozzolans ◽  
Fine Aggregates ◽  
Lime Mortars

In recent years, lime mortars mixed with artificial or natural pozzolans are commonly used in restoration applications. The aim of this work is the assessment of carbonation, pozzolanic reaction, setting time, and mechanical properties of metakaolin–lime mortars mixed with crystalline nano-titania (nT) as additive. The studied mortars consist of hydrated lime and metakaolin in 60/40 ratio (wt%) and fine aggregates of either carbonate or silicate sand. The concentration of the nano-titania is equal to 6 (wt%) of the binder. For comparison purposes, three types of mortars and pastes are designed: Without the addition of nano-titania, with nT activated or not under UV irradiation. The evaluation of the carbonation and pozzolanic reaction over a 1.5-year curing period is carried out through thermal analysis (DTA/TG), infrared spectroscopy (FTIR) and X-ray diffraction analysis (XRD). The uniaxial compression and the three-point bending tests at 28 days, 3 months, and 6 months were carried out to evaluate mechanical properties. The addition of activated nano-titania, due to an increased photocatalytic activity, accelerated the setting of the mortars, improving at the same time the mechanical properties. The plastic behavior of the lime–metakaolin mortars with activated nT was attributed to the evolution of carbonation and pozzolanic reaction.

scholarly journals Characterization of Titanium Nanotube Reinforced Cementitious Composites: Mechanical Properties, Microstructure, and Hydration

Materials ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1617 ◽  
Author(s):  
Hyeonseok Jee ◽  
Jaeyeon Park ◽  
Erfan Zalnezhad ◽  
Keunhong Jeong ◽  
Seung Min Woo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Cement Paste ◽  
Cementitious Materials ◽  
Cement Clinker ◽  
Early Age ◽  
Potential Candidate ◽  
Hydration Kinetics ◽  
Cement Pastes ◽  
Viable Solution ◽  
First Time

In recent years, nano-reinforcing technologies for cementitious materials have attracted considerable interest as a viable solution for compensating the poor cracking resistance of these materials. In this study, for the first time, titanium nanotubes (TNTs) were incorporated in cement pastes and their effect on the mechanical properties, microstructure, and early-age hydration kinetics was investigated. Experimental results showed that both compressive (~12%) and flexural strength (~23%) were enhanced with the addition of 0.5 wt.% of TNTs relative to plain cement paste at 28 days of curing. Moreover, it was found that, while TNTs accelerated the hydration kinetics of the pure cement clinker phase (C3S) in the early age of the reaction (within 24 h), there was no significant effect from adding TNTs on the hydration of ordinary Portland cement. TNTs appeared to compress the microstructure by filling the cement paste pore of sizes ranging from 10 to 100 nm. Furthermore, it could be clearly observed that the TNTs bridged the microcracks of cement paste. These results suggested that TNTs could be a great potential candidate since nano-reinforcing agents complement the shortcomings of cementitious materials.

scholarly journals CONTINUOUS MICROSTRUCTURAL CORRELATION OF SLAG/SUPERPLASTICIZER CEMENT PASTES BY HEAT AND IMPEDANCE METHODS VIA FRACTAL ANALYSIS

Fractals ◽  
2017 ◽  
Vol 25 (04) ◽  
pp. 1740003 ◽  
Author(s):  
S. W. TANG ◽  
R. J. CAI ◽  
Z. HE ◽  
X. H. CAI ◽  
H. Y. SHAO ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Fractal Analysis ◽  
Setting Time ◽  
Blended Cement ◽  
Impedance Measurement ◽  
Heat Evolution ◽  
Early Age ◽  
Contact Impedance ◽  
Cement Pastes ◽  
Early Age Hydration

This paper presents a preliminary work to evaluate the influence of slag and superplasticizer on the early-age hydration of cement pastes by an innovative non-contact impedance measurement, heat evolution method, compressive strength and setting time tests. Besides, the cumulative pore volume obtained from modulus and phase of impedance in different hydration sections is taken to continuously correlate the cumulative heat releasing of cement pastes via the fractal analysis. Retarded phenomena and mechanism of hydration in cement pastes incorporated with slag and superplasticizer are studied, respectively. It is found that the compressive strength and setting time have a good linear relation with the slag amount in blended cement pastes.

Influence of the Variability of Limestone and Fly Ash on the Setting and Mechanical Properties of a Moroccan Composite Cement

2022 ◽  
Author(s):  
Nisrine El Fami ◽  
Hind Agourrame ◽  
Nacer Khachani ◽  
Ali Boukhari ◽  
Adeljebbar Diouri
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Setting Time ◽  
Physical And Mechanical Properties ◽  
High Energy ◽  
Pozzolanic Reaction ◽  
Cement Industry ◽  
Chemical Compositions ◽  
Significant Prolongation ◽  
Cement Manufacturing

The Moroccan cement industry is looking for new processes to effectively minimize the high energy costs associated to cement manufacturing. This work presents the effect of three types of limestone with different chemical compositions and different CaCO3 contents on the physical and mechanical properties of resulting composite cements by the addition of fly ash in the proportions by weight of: 5 % and 10 %. The samples are studied in order to evaluate the interaction between different types of limestone and fly ash. Ternary cements based on fly ash-limestone-clinker induce a significant prolongation of the setting time compared to binary cements based on limestone-clinker. The substitution of clinker by limestone induces an improvement in mechanical strength compared to ternary cements in the first days; at 28 days, cements prepared with fly ashes reach significant strength due to their pozzolanic reaction.

Study on the pozzolanic reaction of clay brick powder in blended cement pastes

2019 ◽  
Vol 213 ◽  
pp. 209-215 ◽  
Author(s):  
Jiahu Shao ◽  
Jianming Gao ◽  
Yasong Zhao ◽  
Xuemei Chen
Keyword(s):  
Blended Cement ◽  
Pozzolanic Reaction ◽  
Clay Brick ◽  
Cement Pastes ◽  
Brick Powder

The Role of Nanotechnology in Subgrade and Pavement Engineering: A Review

2020 ◽  
Vol 20 (8) ◽  
pp. 4607-4618 ◽  
Author(s):  
Ling Zeng ◽  
Liuyi Xiao ◽  
Junhui Zhang ◽  
Hongyuan Fu
Keyword(s):  
Mechanical Properties ◽  
Asphalt Mixture ◽  
Pozzolanic Reaction ◽  
Performance Ratio ◽  
Hydration Reaction ◽  
Environmental Friendliness ◽  
Cement Pastes ◽  
Soil Particles ◽  
Subgrade Soils ◽  
Pavement Engineering

Nanotechnology is an extension of sciences and technologies that deal with particles less than 100 nm. This paper reviews previous studies on how nanomaterials work and what their advantages are in subgrade and pavement engineering. In subgrade engineering, the nanomaterials particles can not only improve the physicochemical and mechanical properties of subgrade soils by filling the voids between soil particles but also promote hydration reaction between cement and ion exchange between soil particles. In pavement engineering, the water stability, rutting resistance, fatigue resistance and optical properties of flexible pavements are enhanced by adding nanomaterials into the asphalt mixture. Nanosilica enhances the interface between cement pastes and aggregates and promotes the pozzolanic reaction of concrete, thus, mechanical properties of concrete pavements are improved. Compared with traditional materials, nanomaterials play a promising role in subgrade and pavement engineering, benefitting from their environmental friendliness, lower environmental disturbance, better price/performance ratio and higher durability.

scholarly journals Properties of a Three-Component Mineral Road Binder for Deep-Cold Recycling Technology

Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3585
Author(s):  
Zdzisława Owsiak ◽  
Przemysław Czapik ◽  
Justyna Zapała-Sławeta
Keyword(s):  
Setting Time ◽  
Total Content ◽  
Hydrated Lime ◽  
Cement Pastes ◽  
Free Lime ◽  
Cement Production ◽  
The Road ◽  
Mortar Strength ◽  
Binder Composition ◽  
Cold Recycling

This study examined the physical properties of a three-component mineral binder that is typically used in deep-cold recycling. Test binders were produced using Portland cement, hydrated lime, and cement bypass dust (CBPD) as a byproduct derived from cement production. The suitability of CBPD for use in road binders was assessed. Effects of the three-component binder composition on the setting time, soundness, consistency, and tensile and compressive strengths of the cement pastes and mortars were determined. The pastes and mortars of the same consistency obtained at different w/b ratios were tested. On this basis, the mixture proportions resulting in road binders satisfying the requirements of PN-EN 13282-2:2015 were determined. By mixing cement, lime, and CBPD during the tests, binder classes N1 to N3 were obtained. The replacement of 40% of cement mass with the CBPD high in free lime produced road binders suitable for recycled base layers. The total content of CBPD and hydrated lime in the road binder should not exceed 50% by mass. The potential risk of mortar strength reduction due to KCl recrystallization was discussed.

scholarly journals Studying physico-mechanical properties of cement pastes in presences of blend polymer as chemical admixtures

2015 ◽  
Vol 4 (3) ◽  
pp. 297 ◽  
Author(s):  
Elsayed Negim ◽  
G. Yeligbayeva ◽  
Rimma Niyazbekova ◽  
R. Rakhmetullayeva ◽  
A.A Mamutova ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Setting Time ◽  
Hardened Cement ◽  
Sem Images ◽  
Cement Pastes ◽  
Setting Times ◽  
Blend Ratios ◽  
Hardened Cement Pastes ◽  
Blend Polymer

<p>Physico-mechanical properties of cement pastes were studied by setting time, combined water, compressive strength, SEM as well as porosity in presence of blend polymers. Blend polymers were used based on polyvinyl alcohol and carbamide with blend ratios 20/80, 40/60 and 80/20 respectively. The addition of blend polymers to cement pastes affected the physico-mechanical properties of cement pastes. As the content of carbamide in the polymer blends decreased, the water of consistency decreased, whereas the setting times (initial &amp; final) were elongated. The combined water content and compressive strength of the hardened cement pastes were increased at all ages of hydration. The SEM images showed that the addition of these polymers to cement material improves the dispensability and workability of cement pastes.</p>

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