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

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.

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.

Characterization of eco-substituted cement containing waste ground calcined clay brick

2017 ◽  
Vol 44 (11) ◽  
pp. 956-961 ◽  
Author(s):  
Ghania Nigri ◽  
Yacine Cherait ◽  
Soraya Nigri
Keyword(s):  
Cement Hydration ◽  
Blended Cement ◽  
Pozzolanic Reaction ◽  
Partial Replacement ◽  
Optimal Composition ◽  
Clay Brick ◽  
Calcined Clay ◽  
Blended Cements ◽  
Setting Times

This paper discusses the potentialities of using waste bricks as a partial replacement of clinker in blended cement. The blended cements are produced by grinding and mixing clinker, waste brick and gypsum. Eight mixtures containing 0 to 35% of bricks as a clinker replacement are prepared and characterized. Partially replacing clinker by brick results in early strength, but are lower than that of the reference. However, at 90 days, the strengths are greater than that reference. The setting times and the shrinkages were reduced. Blended cement has been formulated with optimal composition of 10% of waste brick. The microstructure of the paste was studied using scanning electron microscopy and the evolution of cement hydration was studied by Fourier transform infrared spectroscopy. It was concluded that the binder with 10% of brick shows a dense and homogeneous particles distribution. The pozzolanic reaction occurs through the decreases of the amorphous silica during hydration.

scholarly journals Fire Resistance of Sewage Sludge Ash Blended Cement Pastes

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
M. A. Tantawy ◽  
A. M. El-Roudi ◽  
Elham M. Abdalla ◽  
M. A. Abdelzaher
Keyword(s):  
Sewage Sludge ◽  
Fire Resistance ◽  
Calcium Silicate ◽  
Blended Cement ◽  
Total Porosity ◽  
Pozzolanic Reaction ◽  
Cement Matrix ◽  
Cement Pastes ◽  
Sewage Sludge Ash ◽  
Sludge Ash

The aim of the present study is to investigate the hydration characteristics and the fire resistance of sewage sludge ash blended cement pastes by the determination of compressive strength, bulk density, and total porosity in addition to XRD and SEM techniques. Sewage sludge ash modifies the hydration of cement because of its pozzolanic reaction with portlandite favoring the formation of crosslinked fibrous calcium silicate of low Ca/Si ratio. Hence, it was concluded that thermal damage of cement pastes after the exposure to high treatment temperatures (i.e., crack formation and loss of mechanical properties) was effectively reduced with sewage sludge as content up to 20 wt% because of that the presence of crosslinked fibrous calcium silicate strengthens the cement matrix.

scholarly journals Effects of Blended-Cement Paste Chemical Composition Changes on Some Strength Gains of Blended-Mortars

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Mehmet Serkan Kirgiz
Keyword(s):  
Tap Water ◽  
Blended Cement ◽  
Cement Clinker ◽  
Chemical Compositions ◽  
Cement Pastes ◽  
Blended Cements ◽  
Brick Powder ◽  
Cement Mortars ◽  
Marble Powder ◽  
Silica Oxide

Effects of chemical compositions changes of blended-cement pastes (BCPCCC) on some strength gains of blended cement mortars (BCMSG) were monitored in order to gain a better understanding for developments of hydration and strength of blended cements. Blended cements (BC) were prepared by blending of 5% gypsum and 6%, 20%, 21%, and 35% marble powder (MP) or 6%, 20%, 21%, and 35% brick powder (BP) for CEMI42.5N cement clinker and grinding these portions in ball mill at 30 (min). Pastes and mortars, containing the MP-BC and the BP-BC and the reference cement (RC) and tap water and standard mortar sand, were also mixed and they were cured within water until testing. Experiments included chemical compositions of pastes and compressive strengths (CS) and flexural strengths (FS) of mortars were determined at 7th-day, 28th-day, and 90th-day according to TS EN 196-2 and TS EN 196-1 present standards. Experimental results indicated that ups and downs of silica oxide (SiO2), sodium oxide (Na2O), and alkali at MP-BCPCC and continuously rising movement of silica oxide (SiO2) at BP-BCPCC positively influenced CS and FS of blended cement mortars (BCM) in comparison with reference mortars (RM) at whole cure days as MP up to 6% or BP up to 35% was blended for cement.

Hydration and strength evolution of air-cured zeolite-rich tuffs and siltstone blended cement pastes at low water-to-binder ratio

Clay Minerals ◽  
2015 ◽  
Vol 50 (1) ◽  
pp. 133-152 ◽  
Author(s):  
M.H. Cornejo ◽  
J. Elsen ◽  
C. Paredes ◽  
H. Baykara
Keyword(s):  
Compressive Strength ◽  
Blended Cement ◽  
Cementitious Materials ◽  
Pozzolanic Reaction ◽  
Supplementary Cementitious Materials ◽  
Experimental Conditions ◽  
Cement Pastes ◽  
Carbonation Reaction ◽  
Curing Conditions ◽  
Strength Evolution

AbstractThis contribution is the second part of an in-depth study on the hydration and strength evolution of blended cement pastes at a water to binder (W/B) ratio of 0.3, cured by two different methods. The blended cement pastes showed significant hydration up to 7 days, when almost all of the hydration products had already formed; thereafter, carbonation played an important role up to, and possibly beyond, 91 days. Likewise, the hydration of alite (tricalcium silicate, Ca3SiO5, C3S) proceeded up to 14 days and then started to slow down. However, the hydration of belite (dicalcium silicate, Ca2SiO4, C2S) was affected most strongly, as it nearly ceased, under the air-curing conditions. During hydration, some of the blended cement pastes had a larger calcium hydroxide (CH) content than the unblended (plain) ones. The accelerating effects of the addition of supplementary cementitious materials (SCMs), the air-curing conditions and the low W/B ratio may explain these unusual results. Under these experimental conditions, the water incorporated into hydrates was about 50% of the total amount of water used during full hydration of the cement pastes. The pozzolanic reaction predominated during the early ages, but disappeared as time passed. In contrast, the carbonation reaction increased by consuming ∼45% of the total amount of CH produced after aging for 91 days. Only one blended cement paste reached the compressive strength of the plain cements. The blended cement pastes containing 5% of the zeolitic tuffs, Zeo1 or Zeo2, or 10% of the calcareous siltstone, Limo, developed the greatest compressive strength under the experimental conditions used in this study.

scholarly journals The Combined Effect of the Initial Cure and the Type of Cement on the Natural Carbonation, the Portlandite Content, and Nonevaporable Water in Blended Cement

2017 ◽  
Vol 2017 ◽  
pp. 1-17 ◽  
Author(s):  
Saida Boualleg ◽  
Mohamed Bencheikh ◽  
Larbi Belagraa ◽  
Aziz Daoudi ◽  
Mohamed Aziz Chikouche
Keyword(s):  
Blended Cement ◽  
Cementitious Materials ◽  
Pozzolanic Reaction ◽  
Supplementary Cementitious Materials ◽  
Cement Pastes ◽  
Slowing Down ◽  
Carbonation Process ◽  
Two Parameters ◽  
Physical And Chemical ◽  
Natural Carbonation

The aim of this work is to better understand the physical and chemical phenomena involved in hydrated mix (clinker + addition) during the natural carbonation process, to characterize cement with supplementary cementitious materials (SCMs) under various curing environment. The prepared cement pastes were characterized by thermogravimetric analysis. The results showed a considerable influence of the environment on the properties of mortars and cement and a perfect correlation between compressive strength, natural carbonation, nonevaporable water, and portlandite content. It was observed that the reduction of the curing period makes the mortars more sensitive. The kinetics of process was evaluated from Ca(OH)2 content and nonevaporable water contained in mortars. These two parameters reflect the hydration progress of the water/cement ratio studied. The weight loss due to Ca(OH)2 decomposition, calculated by DTA/TG analysis, shows the effect of the pozzolanic reaction and the natural carbonation. The supplementary cementitious materials (SCMs) play a considerable role in the slowing down of the aggression environment.

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