Effect of steam curing regimes on temperature and humidity gradient, permeability and microstructure of concrete

2021 ◽  
Vol 281 ◽  
pp. 122562
Author(s):  
Jinyan Shi ◽  
Baoju Liu ◽  
Feng Zhou ◽  
Shuai Shen ◽  
Aofei Guo ◽  
...  
Keyword(s):  
Steam Curing ◽  
Humidity Gradient ◽  
Temperature And Humidity ◽  
Curing Regimes

Mechanical Properties of Reactive Powder Concrete Containing Fly Ash under Different Curing Regimes

2014 ◽  
Vol 597 ◽  
pp. 320-323 ◽  
Author(s):  
De Hong Wang ◽  
Yan Zhong Ju ◽  
Wen Zhong Zheng
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Flexural Strength ◽  
Ash Content ◽  
Reactive Powder Concrete ◽  
Steam Curing ◽  
Cement Ratio ◽  
Reactive Powder ◽  
Curing Regimes

Mechanical properties of reactive powder concrete (RPC) containing fly ash were investigated under different curing regimes (standard and steam curing) in this study. The experimental results indicate that, flexural strength of RPC increased considerably after steam curing, compared to the standard curing. Steam curing had no significant effect on compressive strength of RPC. Increasing the fly ash content improved the flexural strength of RPC under all curing regimes considerably. The compressive strength reached a maximum (103.8MPa) when the fly to ash and cement ratio is 0.3.

Thermal Conduction Experiments on Compacted GMZ Bentonite Blocks as the Potential Buffer Materials for HLW Disposal Purpose

2010 ◽  
Author(s):  
Guang-yuan Ren ◽  
Xiao-dong Liu ◽  
Qing-chun Chen ◽  
Guo-ping Zhu ◽  
Quan-shui Chen
Keyword(s):  
Relative Humidity ◽  
Temperature Gradient ◽  
Thermal Conduction ◽  
Gmz Bentonite ◽  
Radial Temperature Gradient ◽  
Moisture Movement ◽  
Radial Temperature ◽  
Humidity Gradient ◽  
Check Points ◽  
Temperature And Humidity

Compacted Na-bentonite blocks, with the original water content of 9% and compacting density of 1800kg/m3, from the Gaomiaozi (GMZ) deposit in Inner Mongolia Autonomous Region have been experienced about two months experiment in order to reveal the transmission patterns of temperature and the heat induced moisture movement in GMZ Na-bentonite blocks under high-level radioactive waste repository-like conditions. Based on the design, temperature and humidity composed micro-sensors have been used and allocated in different positions in the bentonite blocks as the check points of the experiment. There are two thermal conduction stages in GMZ bentonite blocks in a closed cylinder heat conduction system. In the first stage, the temperature at the check points in the bentonite blocks near the heater in the centre of the cylinder increased to 55°C in 20 hours, and the temperature at the check points distributed near the edge of the cylinder reached about 48°C in the same period. The temperature was maintained at about 60°C for about 35 days in the first stage. The heat induced moisture movement in bentonite blocks in the cylinder is different from changes of the temperature. The relative humidity at the check points near the heater increased quickly at the beginning of the heating, and then slowly decreased with the temperature maintained at 60°C. The average radial temperature gradient (GT) and radial relative humidity gradient (GHR) in bentonite blocks are 0.85°C/cm and 1.32%/cm respectively in the first stage. At the end of the first thermal conduction stage, the temperature of heater was slowly increased into 85°C and maintained this temperature for about 25 days as the second thermal conduction stage. The transmission patterns of temperature and the heat induced moisture movement in bentonite blocks are similar to the first stage. However, the radial temperature and humidity gradients are higher than that in the first stage. The average radial temperature gradient (GT) and radial relative humidity gradient (GHR) in bentonite blocks are 1.57°C/cm and 1.89%/cm respectively in the second stage.

The effect of steam curing regimes on the chloride resistance and pore size of high–strength green concrete

2021 ◽  
Vol 280 ◽  
pp. 122409
Author(s):  
Abdullah M. Zeyad ◽  
Megat Azmi Megat Johari ◽  
Ahemd Abutaleb ◽  
Bassam A. Tayeh
Keyword(s):  
Pore Size ◽  
High Strength ◽  
Steam Curing ◽  
Green Concrete ◽  
Chloride Resistance ◽  
Curing Regimes

Influence of steam curing regimes on the properties of ultrafine POFA-based high-strength green concrete

2021 ◽  
Vol 38 ◽  
pp. 102204
Author(s):  
Abdullah M. Zeyad ◽  
Megat Azmi Megat Johari ◽  
Yousef R. Alharbi ◽  
Aref A. Abadel ◽  
Y.H. Mugahed Amran ◽  
...  
Keyword(s):  
High Strength ◽  
Steam Curing ◽  
Green Concrete ◽  
Curing Regimes

scholarly journals A Comparative Study on the Mechanical Properties and Microstructure of Cement-Based Materials by Direct Electric Curing and Steam Curing

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7407
Author(s):  
Zhihan Yang ◽  
Youjun Xie ◽  
Jionghuang He ◽  
Fan Wang ◽  
Xiaohui Zeng ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Energy Consumption ◽  
Hydration Degree ◽  
Steam Curing ◽  
Cement Based Materials ◽  
Curing Methods ◽  
Temperature Controlled ◽  
Stable Growth ◽  
Curing Method ◽  
Curing Regimes

Direct electric curing (EC) is a new green curing method for cement-based materials that improves the early mechanical properties via the uniform high temperature produced by Joule heating. To understand the effects of EC and steam curing (SC) on the mechanical properties and microstructure of cement-based materials, the mortar was cured at different temperature-controlled curing regimes (40 °C, 60 °C, and 80 °C). Meanwhile, the mechanical properties, hydrates and pore structures of the specimens were investigated. The energy consumption of the curing methods was compared. The results showed that the EC specimens had higher and more stable growth of mechanical strength. The hydration degree and products of EC samples were similar to that of SC samples. However, the pore structure of EC specimens was finer than that of SC specimens at different curing ages. Moreover, the energy consumption of EC was much lower than that of SC. This study provides an important technical support for the EC in the production of energy-saving and high early-strength concrete precast components.

scholarly journals A Comparative Study on the Mechanical Properties and Microstructure of Cement-Based Materials by Direct Electric Curing and Steam Curing

2021 ◽  
Author(s):  
Zhihan Yang ◽  
Youjun Xie ◽  
Jionghuang He ◽  
Fan Wang ◽  
Xiaohui Zeng ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Energy Consumption ◽  
Pore Structure ◽  
Steam Curing ◽  
Cement Based Materials ◽  
Curing Methods ◽  
Stable Growth ◽  
Curing Method ◽  
Curing Regimes ◽  
Better Than

Direct electric curing (EC) is a new green curing method for cement-based materials that improves the early mechanical properties via the uniform high temperature produced by Joule heating. To understand the effects of EC and steam curing (SC) on the mechanical properties and microstructure of cement-based materials, the mortar was cured at different temperature-controlled curing regimes (40°C, 60°C and 80°C). Meanwhile, mechanical properties, hydrate phase and pore structure of specimens were investigated. The energy consumption of two curing methods was compared and analyzed. The results show that the EC specimens have better and more stable growth of mechanical strength. The pore structure of EC specimen is also better than that of SC specimen at different maintenance ages. However, the hydration degree and products of samples cured by EC are similar to that SC samples. The energy consumption of EC is lower than SC. This study provides an important technical support for the EC in the production of energy-saving and high early-strength concrete precast components.

Cryo-TEM of amphiphilic polymer and amphiphile/polymer solutions

1993 ◽  
Vol 51 ◽  
pp. 876-877
Author(s):  
Yeshayahu Talmon
Keyword(s):  
Microstructural Characterization ◽  
Building Blocks ◽  
Quantitative Information ◽  
Physical Models ◽  
Specimen Preparation ◽  
Time Resolved ◽  
Temperature Changes ◽  
Temperature And Humidity ◽  
Microstructured Fluids ◽  
Air Streams

To achieve complete microstructural characterization of self-aggregating systems, one needs direct images in addition to quantitative information from non-imaging, e.g., scattering or Theological measurements, techniques. Cryo-TEM enables us to image fluid microstructures at better than one nanometer resolution, with minimal specimen preparation artifacts. Direct images are used to determine the “building blocks” of the fluid microstructure; these are used to build reliable physical models with which quantitative information from techniques such as small-angle x-ray or neutron scattering can be analyzed.To prepare vitrified specimens of microstructured fluids, we have developed the Controlled Environment Vitrification System (CEVS), that enables us to prepare samples under controlled temperature and humidity conditions, thus minimizing microstructural rearrangement due to volatile evaporation or temperature changes. The CEVS may be used to trigger on-the-grid processes to induce formation of new phases, or to study intermediate, transient structures during change of phase (“time-resolved cryo-TEM”). Recently we have developed a new CEVS, where temperature and humidity are controlled by continuous flow of a mixture of humidified and dry air streams.

Sign in / Sign up

Export Citation Format

Share Document