Discussion on Measuring Methods of Deformation of Concrete at early Ages

2014 ◽  
Vol 584-586 ◽  
pp. 1985-1991
Author(s):  
Qi Liu ◽  
Ying Zi Yang ◽  
Hong Wei Deng
Keyword(s):  
Measurement Method ◽  
Mechanical Performance ◽  
Test Methods ◽  
Deformation Monitoring ◽  
Early Age ◽  
Existing Problems ◽  
Flat Base ◽  
Deformation Law ◽  
Early Age Concrete ◽  
Technical Solutions

The deformation law of concrete at early age not only affects the shrinkage and cracking of concrete structure in construction, but also further influences its mechanical performance, safety and durability. Based on the existing test methods of cementitious material deformation at early age and aimed at the existing problems, this paper puts forward five kinds of technical solutions to improve the measurement method. Try to use the change in light signals, the electrical signals and leverage-buoyancy method to implement the automatic and continuous deformation monitoring of early-age concrete. Lastly the combination of corrugated pipe, tilt flat base and eddy-current transducer was recommended as the optimal non-contact measurement method for monitoring the deformation of early-age concrete.

Very early age concrete hydration characterization monitoring using piezoceramic based smart aggregates

2013 ◽  
Vol 22 (8) ◽  
pp. 085025 ◽  
Author(s):  
Qingzhao Kong ◽  
Shuang Hou ◽  
Qing Ji ◽  
Y L Mo ◽  
Gangbing Song
Keyword(s):  
Early Age ◽  
Concrete Hydration ◽  
Early Age Concrete

scholarly journals Characterization of Moisture Diffusion in Cured Concrete Slabs at Early Ages

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Xiao Zhang ◽  
Hongduo Zhao
Keyword(s):  
Process Model ◽  
Model Simulation ◽  
Moisture Diffusion ◽  
Experimental Results ◽  
Concrete Slabs ◽  
Model Parameters ◽  
Early Age ◽  
Water Curing ◽  
Early Age Concrete

The objective of this paper is to investigate the characterization of moisture diffusion inside early-age concrete slabs subjected to curing. Time-dependent relative humidity (RH) distributions of three mixture proportions subjected to three different curing methods (i.e., air curing, water curing, and membrane-forming compounds curing) and sealed condition were measured for 28 days. A one-dimensional nonlinear moisture diffusion partial differential equation (PDE) based on Fick’s second law, which incorporates the effect of curing in the Dirichlet boundary condition using a concept of curing factor, is developed to simulate the diffusion process. Model parameters are calibrated by a genetic algorithm (GA). Experimental results show that the RH reducing rate inside concrete under air curing is greater than the rates under membrane-forming compound curing and water curing. It is shown that the effect of water-to-cement (w/c) ratio on self-desiccation is significant. Lower w/c ratio tends to result in larger RH reduction. RH reduction considering both effect of diffusion and self-desiccation in early-age concrete is not sensitive to w/c ratio, but to curing method. Comparison between model simulation and experimental results indicates that the improved model is able to reflect the effect of curing on moisture diffusion in early-age concrete slabs.

scholarly journals Monitoring of the ultrasonicP-wave velocity in early-age concrete using Smart Aggregates

2012 ◽  
Vol 1 ◽  
pp. 01001 ◽  
Author(s):  
Cédric Dumoulin ◽  
Grigoris Karaiskos ◽  
Jérôme Carette ◽  
Stéphanie Staquet ◽  
Arnaud Deraemaeker
Keyword(s):  
Wave Velocity ◽  
Early Age ◽  
Early Age Concrete
Sign in / Sign up

Export Citation Format

Share Document