Shrinkage-reducing admixtures and early-age desiccation in cement pastes and mortars

2001 ◽  
Vol 31 (7) ◽  
pp. 1075-1085 ◽  
Author(s):  
D.P. Bentz ◽  
M.R. Geiker ◽  
K.K. Hansen
Keyword(s):  
Early Age ◽  
Cement Pastes ◽  
Shrinkage Reducing Admixtures

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.

Device for Pore Solution Extraction from Cement-Based Materials and its Application

2016 ◽  
Vol 680 ◽  
pp. 365-369
Author(s):  
Jian Liang Zhang ◽  
An Qun Lu ◽  
Hua Li ◽  
Rui Wang ◽  
Wen Bin Wang ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Pore Solution ◽  
Early Age ◽  
Cement Pastes ◽  
Cement Based Materials ◽  
Different Ages ◽  
Low Rate ◽  
Relevant Factors

In this paper, a device for pore solution extraction from cement-based materials was presented, The relevant Factors of Efficiency of Pore Solution Extraction and the effects of squeezing pressures on the chemical concentrations of pore solutions were studied. The results shows, the efficiency of pore solution extraction can be effected by pressure values, squeezing duration, pressure maintaining time; A low rate of pressures loading is suitable for early-age cement pastes, and long-term samples can take larger rate; 30 minutes loading time can be adopted for specimens with all the different ages; no significant differences were observed regarding the chemical composition (Na and K) of the pore solution extracted between 300 and 900MPa.

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 EARLY AGE POROSITY AND PORE SIZE DISTRIBUTION OF CEMENT PASTE WITH FLUE GAS DESULPHURISATION (FGD) WASTE

2013 ◽  
Vol 19 (5) ◽  
pp. 622-627 ◽  
Author(s):  
Jamal M. Khatib ◽  
Pritpal S. Mangat ◽  
Lee Wright
Keyword(s):  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Cement Paste ◽  
Flue Gas ◽  
Early Stage ◽  
Early Age ◽  
Cement Pastes ◽  
Binder Ratio ◽  
Water To Binder Ratio

This paper is part of a wide-ranging investigation on the use of flue gas desulphurisation (FGD) waste in cement-based materials. It reports the results on the porosity and pore size distribution of cement paste containing varying amounts of simulated FGD waste. The water to binder ratio was 0.5. The binder consists of cement and simulated FGD. The FGD is a combination of fly ash and gypsum ranging from 0% to 100%. Cement in the pastes was partially replaced with 25% FGD (by weight). The porosity and pore size distribution of cement pastes was determined during the early stage of hydration. Increasing the amount of gypsum does not increase the pore volume. However, increasing the amount of gypsum in the paste leads to an increase in the threshold diameter and a decrease in the percentage of small pores in the paste, both indicating a coarser pore structure. The results of this investigation were compared with data at longer curing periods.

Effect of free water removal from early-age hydrated cement pastes on thermal analysis

2009 ◽  
Vol 23 (11) ◽  
pp. 3431-3438 ◽  
Author(s):  
Elke Knapen ◽  
Ozlem Cizer ◽  
Koenraad Van Balen ◽  
Dionys Van Gemert
Keyword(s):  
Thermal Analysis ◽  
Free Water ◽  
Early Age ◽  
Water Removal ◽  
Hydrated Cement ◽  
Cement Pastes
Sign in / Sign up

Export Citation Format

Share Document