scholarly journals EFFECT OF CURING TEMPERATURE ON THE PHYSICAL PROPERTY AND HYDRATION OF CEMENTITIOUS MATERIAL BASED ON PORTLAND CEMENT-CALUCIUM ALUMINATE CEMENT-ANHYDRITE SYSTEM

2015 ◽  
Vol 69 (1) ◽  
pp. 214-220
Author(s):  
Hirokatsu MORI ◽  
Daiki ATARASHI ◽  
Masahiro MIYAUCHI ◽  
Etsuo SAKAI
Keyword(s):  
Portland Cement ◽  
Physical Property ◽  
Cementitious Material ◽  
Curing Temperature ◽  
Aluminate Cement

scholarly journals The use of a volcanic material as filler in self-compacting concrete production for lower strength applications

2017 ◽  
Vol 67 (325) ◽  
pp. 111 ◽  
Author(s):  
D. Burgos ◽  
A. Guzmán ◽  
K. M.A. Hossain ◽  
S. Delvasto
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Cementitious Material ◽  
Total Weight ◽  
Self Compacting Concrete ◽  
Lower Strength ◽  
Volcanic Material ◽  
Fine Powders ◽  
Slump Flow ◽  
Concrete Production

This study evaluates the use of large amounts of fine powders (fillers) derived from a Colombian volcanic material into the production of self-compacting concrete (SCC) for lower strength applications. The effects on SCC properties were studied with the incorporation of up to 50% of volcanic material of Tolima (MVT) as a partial substitute of the total weight of Portland cement. The workability was determined through slump flow, V-funnel, and L-box test. The compressive strength results were analyzed statistically by MINITAB. These demonstrated that 30% (by total weight of cementitious material) was the maximum allowable percentage of MVT to be used in the production of SCCs. Based on this, mechanical and permeability properties of SCC MVT 30% were evaluated at 28, 90 y 360 curing days. SCC MVT 30% exhibited compressive strength of 21 and 27 MPa after 28 and 360 days of curing, respectively.

scholarly journals Hydration and Microwave Curing Temperature Interactions of Repair Mortars

2021 ◽  
Vol 03 (04) ◽  
pp. 1-1
Author(s):  
Pal S. Mangat ◽  
◽  
Shahriar Abubakri ◽  
Konstantinos Grigoriadis ◽  
Vincenzo Starinieri ◽  
...  
Keyword(s):  
Portland Cement ◽  
Heat Of Hydration ◽  
Curing Temperature ◽  
Early Age ◽  
Normal Density ◽  
Concrete Repair ◽  
Microwave Curing ◽  
Polymer Addition ◽  
Curing Period ◽  
Repair Materials

Microwave curing of repair patches provides an energy efficient technique for rapid concrete repair. It has serious economic potential due to time and energy saving especially for repairs in cold weather which can cause work stoppages. However, the high temperatures resulting from the combination of microwave exposure and accelerated hydration of cementitious repair materials need to be investigated to prevent potential durability problems in concrete patch repairs. This paper investigates the time and magnitude of the peak hydration temperature during microwave curing (MC) of six cement based concrete repair materials and a CEM II mortar. Repair material specimens were microwave cured to a surface temperature of 40-45 °C while their internal and surface temperatures were monitored. Their internal temperature was further monitored up to 24 hours in order to determine the effect of microwave curing on the heat of hydration. The results show that a short period of early age microwave curing increases the hydration temperature and brings forward the peak heat of hydration time relative to the control specimens which are continuously exposed to ambient conditions (20 °C, 60% RH). The peak heat of hydration of normal density, rapid hardening Portland cement based repair materials with either pfa or polymer addition almost merges with the end of microwave curing period. Similarly, lightweight polymer modified repair materials also develop heat of hydration rapidly which almost merges with the end of microwave curing period. The peak heat of hydration of normal density ordinary Portland cement based repair materials, with and without polymer addition, occurs during the post microwave curing period. The sum of the microwave curing and heat of hydration temperatures can easily exceed the limit of about 70 °C in some materials at very early age, which can cause durability problems.

Effect of Temperature on Hydration Performance of Portland Cement

2013 ◽  
Vol 328 ◽  
pp. 863-866
Author(s):  
Jun Liu ◽  
Yun Zhang ◽  
Run Qing Liu ◽  
Fang Zhi Lin ◽  
Zi Yan Huang
Keyword(s):  
Portland Cement ◽  
Mechanical Strength ◽  
Curing Temperature ◽  
Effect Of Temperature ◽  
Temperature Decrease ◽  
Hydration Products ◽  
Hydration Time ◽  
Strength Change ◽  
Different Temperatures ◽  
Change Trend

The mechanical strength change trend of Portland cement at different temperatures (+5°C, 0°C,-5°C,-10°C) was researched, and hydration performance and slurry structure of Portland cement was studied. Results showed that hydration process of Portland cement didn't vary with the lowering of curing temperature, but each stage of hydration time extended. The temperature decrease prolonged formation time of hydration products, making the early microstructure to loose, produces more pores, and causes the early mechanical strength of Portland cement to decrease.

Effect of Curing Humidity on Stiffness of Cement Based Mortars with Recycled Fillers

2016 ◽  
Vol 825 ◽  
pp. 19-22
Author(s):  
Mirek Jarolím ◽  
Andrej Osvald ◽  
Václav Nežerka ◽  
Jaroslav Topič ◽  
Richard Ťoupek ◽  
...  
Keyword(s):  
Portland Cement ◽  
Elastic Stiffness ◽  
Cementitious Material ◽  
Recycled Concrete ◽  
Impulse Excitation ◽  
The Relationship ◽  
Non Destructive ◽  
Influence Of Hydration ◽  
Common Laboratory ◽  
Secondary Hydration

Values of the dynamic Young’s modulus were monitored on cement-based samples containing recycled concrete. In particular, the study was focused on investigation of the relationship between the elastic stiffness and amount of recycled microfiller to replace Portland cement. The amount of the microfiller was ranging between 30 and 70 % per weight of the samples. The samples were cured in common laboratory conditions for 50 days, followed by their placement into a water bath for 2 days and consequent natural drying period for 6 days. The development of elastic stiffness was monitored using non-destructive impulse excitation method in order to demonstrate the influence of hydration when the specimens are stored in high humidity. The increase of elastic stiffness proves a secondary hydration of both – Portland cement and cement grains from the recycled cementitious material.

scholarly journals Calorimetry in the studies of by-pass cement kiln dust as an additive to the calcium aluminate cement

2019 ◽  
Vol 138 (6) ◽  
pp. 4561-4569 ◽  
Author(s):  
Wiesława Nocuń-Wczelik ◽  
Katarzyna Stolarska
Keyword(s):  
Portland Cement ◽  
Rheological Properties ◽  
Calcium Aluminate ◽  
Calcium Aluminate Cement ◽  
Cement Kiln ◽  
Phase Assemblage ◽  
Chemical Shrinkage ◽  
High Calcium ◽  
Kinetics Of ◽  
Aluminate Cement

Abstract The studies focused on the kinetics of early hydration in the high-calcium aluminate cement (CAC 70)—by-pass cement kiln dusts (BPCKD)—mixtures. For this purpose, the mixtures of cement with this additive or with some potential constituents of dusts were produced. The microcalorimeter was applied to follow the kinetics of hydration. The investigations with the aim of finding the relationship between the components of initial mixtures and the modification of hydration process were carried out. The rheological properties were characterized, and the chemical shrinkage characteristics were produced. The phase assemblage characterization and microscopic observations were done as well. In case of the high-calcium aluminate-based binders, the modification of setting process was observed; the rheological properties and chemical shrinkage were affected too. The acceleration of heat evolution—the shortening of so-called induction period in the presence of BPCKD additive—was observed. The results were compared to those obtained for the CAC with ordinary Portland cement additive. The results of calorimetric measurements are discussed in terms of the chemical and phase assemblage of this additive as compared to the Portland cement clinker precursors and potassium chloride—the solid and liquid components of the dust.

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