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.

Relationship between Compressive Strength and Young's Modulus of Cement Paste with Recycled Concrete Powder

2016 ◽  
Vol 722 ◽  
pp. 254-259 ◽  
Author(s):  
Jaroslav Topič ◽  
Jan Trejbal ◽  
Tomáš Plachý ◽  
Zdeněk Prošek
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
High Speed ◽  
Reference Sample ◽  
Milled Powder ◽  
Recycled Concrete ◽  
Cement Pastes ◽  
Cement Replacement ◽  
Cement Based Materials

This article deals with utilization of recycled concrete in form of high-speed milled powder into cement based materials. Recycled concrete powder in that form is used as microfiller and cement replacement. This article contains results of mechanical properties of the cement pastes with different amount of recycled concrete powder. The mechanical properties as the compressive strength, flexural strength, dynamic Young's and share moduli are observed during 409 days. According to results can be assumed that recycled concrete powder can be used as microfiller and cement replacement under 30 wt. % of total amount. Especially the results of compressive strength are comparable with reference sample. But there are some abnormalities in long term development of the strength that need to be explained.

Mechanism Research of Drying Shrinkage of Cement Pastes Based on the Contact Angle

2014 ◽  
Vol 670-671 ◽  
pp. 391-395
Author(s):  
Kai Wei Song ◽  
Guo Fu Chen ◽  
Hang Zhang ◽  
Cong Li Shi ◽  
Jia Yang
Keyword(s):  
Surface Tension ◽  
Contact Angle ◽  
Pore Water ◽  
Driving Forces ◽  
Pore Solution ◽  
Drying Shrinkage ◽  
Mineral Admixtures ◽  
Water Contact ◽  
Cement Pastes ◽  
Cement Based Materials

Capillary tention is one of the driving forces of shrinkage of cement-based materials, which is related to distribution of pore size, surface tension of pore water, contact angle of pore walls and so on. There are some appropriate test methods for pore diameter and surface tension of cement-based materials, but the contact angle of pore water is rarely related to. This paper showed a new method to test the contact angle of cement-based materials which is based on the principle of thin-layer wicking about surface physical chemistry. Combining Washburn equation x2=(Refft/2) , the contact angle of analog pore solution to cement paste was obtained. The influence of superplasticizers and mineral admixtures on the contact angle and drying shrinkage of cement pastes also were researched. The results showed that the larger contact angle leads to the smaller surface tension of pore solution, which also caused that the capillary wall wass infiltrated more difficultly. As a result, the pressure of pore and the drying shrinkage were both small, vice versa.

Relative Humidity of Blended Cement Pastes in Sealed during Hydration

2013 ◽  
Vol 539 ◽  
pp. 60-63
Author(s):  
Dan Jin ◽  
Wu Yao ◽  
Yi Chen
Keyword(s):  
Relative Humidity ◽  
Blended Cement ◽  
Mineral Admixture ◽  
Mineral Admixtures ◽  
Cement Pastes ◽  
Cement Ratio ◽  
Water To Cement Ratio ◽  
Cement Based Materials ◽  
Different Ages ◽  
Key Factor

As an important part of cement-based materials，water plays an important role during hydration and self-desiccation so the measurement of relative humidity or internal moisture in the research of cement-based materials is vital. In this paper, the measurement samples are blended cement pastes in sealed with different water to cement ratios and different kind of mineral admixtures. The measurement was taken at different ages during hydration to investigate the changes of relative humidity. The result showed that the water to cement ratio was the key factor of affecting the change of relative humidity, and the effect of mineral admixture kind was not very obvious in this experiment.

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.

Monitoring the Chemical Composition of Air in Case of Interplanetary and Long-Term Space Flights: Problems, Approaches, and Solutions

2019 ◽  
Vol 13 (4) ◽  
pp. 685-713
Author(s):  
Sh. Sh. Nabiev ◽  
G. Yu. Grigor’ev ◽  
A. S. Lagutin ◽  
L. A. Palkina ◽  
A. A. Vasil’ev ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Space Flights

A study of the metabolism of two breeds of pig: (With some remarks on a third)

1929 ◽  
Vol 19 (1) ◽  
pp. 140-184 ◽  
Author(s):  
Thomas Deighton
Keyword(s):  
Critical Temperature ◽  
Body Temperature ◽  
Environmental Temperature ◽  
Unit Area ◽  
Skin Colour ◽  
Early Age ◽  
Large White ◽  
Different Ages

The metabolism of a Berkshire and a Middle White pig has been investigated by means of the calorimeters at the School of Agriculture, Cambridge. The general routine and technique of the observations have been as heretofore.Measurements of the fasting katabolism of each of the two pigs have been obtained in a series extending from an early age to maturity, and the phenomena in general follow the lines of those originally discovered in the Large White; but the fasting katabolism of the Middle White was below that of the Large White earlier studied.The fall in body temperature and in metabolism during the fasts were found to be correlated, and the possible effect of skin colour in this matter is noted.The effect of environmental temperature is investigated and reasons are given for supposing that the critical temperature of the Middle White pig is very low.It is concluded that the existence of a maximum somewhere in the curve showing fasting katabolism per unit area at different ages is necessitated by the two physiological facts (a) that warm blooded animals have to be maintained at a temperature which varies only within very narrow limits, and (b) that the processes of growth are accompanied by waste of energy as heat.

scholarly journals Production potential and chemical composition of elephant grass (Pennisetum purpureum Schum.) at different ages for energy purposes

2017 ◽  
Vol 16 (25) ◽  
pp. 1428-1433 ◽  
Author(s):  
Kesia Faria Vidal Ana ◽  
da Costa Barbe Tatiane ◽  
Figueiredo Daher Rogerio ◽  
Eustáquio Almeida Filho Janeo ◽  
Samara Nunes de Lima Roberta ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Pennisetum Purpureum ◽  
Elephant Grass ◽  
Production Potential ◽  
Different Ages ◽  
Pennisetum Purpureum Schum
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