Embedded piezoelectric transducers based early-age hydration monitoring of cement concrete added with accelerator/retarder admixtures

2020 ◽  
pp. 1045389X2096991 ◽  
Author(s):  
Demi Ai ◽  
Chengxing Lin ◽  
Hongping Zhu
Keyword(s):  
Heat Effect ◽  
Hydration Heat ◽  
Strength Development ◽  
Early Age ◽  
Strength Gain ◽  
Element Analysis ◽  
Electromechanical Impedance ◽  
Hardening Process ◽  
Concrete Hydration ◽  
Early Age Hydration

Accelerator/retarder admixtures are often added into concrete to improve its early-age strength, which needs to be effectively monitored during its hardening process. The electromechanical impedance (EMI) technique has validated its effectiveness for concrete hydration monitoring, this study attempted to extend the EMI technique to monitor 28-day age of strength gain in concrete that added with accelerator/retarder admixtures. Two types of new piezoelectric (PZT) transducers namely cement/aluminum embedded PZT (CEP/AEP) were proposed for EMI monitoring. The feasibility of the CEP and AEP was first verified via finite element analysis, where hydration heat effect on the two types of transducers was comparatively evaluated by numerical modeling. In the experiment, CEP/AEP transducers were applied to monitor the strength gain in concrete cubes, where characteristics of EMI signature and its statistical indices including root mean square deviation (RMSD) and mean absolute percentage deviation (MAPD) were analyzed and correlated to strength development in concrete. Monitoring results demonstrated that concrete hydration triggered by retarder/accelerator were successfully captured by EMI signature. RMSD and MAPD indices further indicated that AEP had preferable performance than CEP transducer for monitoring early-age strength gain of concrete, as it could immune from hydration heat effect.

scholarly journals Nondestructive Wireless Monitoring of Early-Age Concrete Strength Gain Using an Innovative Electromechanical Impedance Sensing System

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
C. P. Providakis ◽  
E. V. Liarakos ◽  
E. Kampianakis
Keyword(s):  
Concrete Strength ◽  
Strength Development ◽  
Early Age ◽  
Strength Gain ◽  
Impedance Sensing ◽  
Electromechanical Impedance ◽  
Sensing System ◽  
Cracking Control ◽  
Wireless Usb ◽  
Early Age Concrete

Monitoring the concrete early-age strength gain at any arbitrary time from a few minutes to a few hours after mixing is crucial for operations such as removal of frameworks, prestress, or cracking control. This paper presents the development and evaluation of a potential active wireless USB sensing tool that consists of a miniaturized electromechanical impedance measuring chip and a reusable piezoelectric transducer appropriately installed in a Teflon-based enclosure to monitor the concrete strength development at early ages and initial hydration states. In this study, the changes of the measured electromechanical impedance signatures as obtained by using the proposed sensing system during the whole early-age concrete hydration process are experimentally investigated. It is found that the proposed electromechanical impedance (EMI) sensing system associated with a properly defined statistical index which evaluates the rate of concrete strength development is very sensitive to the strength gain of concrete structures from their earliest stages.

Controlling the early-age hydration heat release of cement paste for deep-water oil well cementing: A new composite designing approach

2021 ◽  
Vol 285 ◽  
pp. 122949
Author(s):  
Da-heng Wang ◽  
Xiao Yao ◽  
Tao Yang ◽  
Wen-rui Xiang ◽  
Ying-tao Feng ◽  
...  
Keyword(s):  
Heat Release ◽  
Cement Paste ◽  
Deep Water ◽  
Hydration Heat ◽  
Early Age ◽  
Oil Well ◽  
Early Age Hydration

Analysis of Model Test Data for CFG Group Piles in Permafrost Areas

2014 ◽  
Vol 501-504 ◽  
pp. 16-19
Author(s):  
Zhao Jian Luan ◽  
Qiang Xin ◽  
Yan Min Jia
Keyword(s):  
Temperature Field ◽  
Heat Effect ◽  
Frozen Soil ◽  
Hydration Heat ◽  
Measured Temperature ◽  
Geological Conditions ◽  
Soil Temperatures ◽  
Concrete Hydration ◽  
Group Piles ◽  
Model Temperature

In this paper, the author simulates geological conditions of permafrost areas, establi-shes CFG group piles indoor model, observes the pile and frozen soil temperature field, then compares the calculated results of the group piles and frozen soil temperatures under concrete hydration heat effect by using ABAQUS with the measured temperature data, thus determines the applicability of ABAQUS for analysis of CFG group piles temperature in permafrost areas, in order to analyze temperature distribution regularities of group piles and frozen soil under concrete hydration heat effect, thermal perturbation range of CFG group piles in permafrost areas, and effects of different concrete molding temperature on model temperature field.

The influence of mechanical activation by vibro-milling on the early-age hydration and strength development of cement

2016 ◽  
Vol 71 ◽  
pp. 53-62 ◽  
Author(s):  
Konstantin Sobolev ◽  
Zhibin Lin ◽  
Yizheng Cao ◽  
Hongfang Sun ◽  
Ismael Flores-Vivian ◽  
...  
Keyword(s):  
Mechanical Activation ◽  
Strength Development ◽  
Early Age ◽  
Early Age Hydration

The Hydration Heat Analysis for Sealing Concrete of Swivel Construction Open Thin Wall Arch

2012 ◽  
Vol 253-255 ◽  
pp. 440-444
Author(s):  
Xiong Hui Feng ◽  
Zi Qiang Zhu ◽  
Zhi Yong Li ◽  
Xin Wu
Keyword(s):  
Simulation Model ◽  
Heat Effect ◽  
Hydration Heat ◽  
Thin Wall ◽  
Arch Bridge ◽  
Boundary Constraint ◽  
Constant Coefficients ◽  
Complex Boundary ◽  
Concrete Hydration ◽  
Simulation Parameters

The sealing concrete of arch bridge will be constructed after swivel construction of it finished. The concrete has such characteristics like huge size, smaller heat radiating area and more complex boundary constraint. According to the cracking situation of this type bridges in recent years, the paper established hydration heat simulation model of it using MIDAS2010 program and numerical analyzed for the model. The hydration heat constant coefficients and placing temperature of the concrete hydration heat effect have been analyzed by simulation parameters base on that. And the results showed that it is an important reason causing the cracking of the concrete.

Early Age Property Study of Phosphate Cement by Electrical Conductivity Measurement

2013 ◽  
Vol 544 ◽  
pp. 409-414
Author(s):  
Zhu Ding ◽  
Xiao Dong Wang ◽  
Bi Qin Dong ◽  
Zong Jin Li ◽  
Feng Xing
Keyword(s):  
Electrical Conductivity ◽  
Fly Ash ◽  
Temperature Rise ◽  
Conductivity Measurement ◽  
Maximum Temperature ◽  
Strength Development ◽  
Initial Reaction ◽  
Early Age ◽  
Electrical Conductivity Measurement ◽  
Hardening Process

The properties and electrical conductivity at early age of magnesium phosphate cement (MPC) was studied. Electrical resistivity or conductivity had been used for explaining the microstructure development of cement materials. In the current study, an electrodeless resistivity meter (ERM) was used to study the early property of MPC, which was mixed with and without fly ash respectively. The hardening process was investigated by the conductivity variation, incorporating with strength development and temperature rise during the initial reaction. The products and microstructure morphology of MPC paste were analysed by XRD and SEM. Results showed the mechanical property of MPC can be improved by fly ash. Fly ash lowers the maximum temperature rise during initial reaction of MPC with water. The electrical conductivity results divids the hardening process of MPC into three stages: acceleration, deceleration and stabilization. Conductivity measurement is an excellent method to explain the hardening process of MPC.

Effect of Gypsum on Strength Development of Steam-Cured Concrete

2011 ◽  
Vol 194-196 ◽  
pp. 1085-1088
Author(s):  
Zhi Min He ◽  
Xiao Ju Shen ◽  
Jun Zhe Liu
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Strength Development ◽  
Early Age ◽  
Strength Gain ◽  
Fly Ashes ◽  
Steam Curing ◽  
Gain Rate ◽  
Early Strength ◽  
Chemical Activator

The use of fly ashes for cement-replacement purposes, especially in high volumes, decreases rate of early strength development of the steam curing concrete. To resolve it, this paper developed a new steam-cured concrete incorporating fly ash and a chemical activator (gypsum). Experiments were conducted to investigate the mechanical properties at early and later ages of steam and standard curing concretes. The corresponding mechanism was also discussed by testing the microstructure of concretes. Results indicate that the demoulding compressive strength of steam curing concrete with 4% gypsum dosage can meet production requirements, and compressive strength of this concrete at later ages increase well. Compared with that of ordinary pure cement steam-cured concrete, concrete with 4% gypsum has a higher compressive strength gain rate. At an early age, addition of the gypsum can distinctly accelerate the extent of hydration of the steam curing fly ash cement systems, and thus the microstructure of concrete becomes denser. However, in standard curing condtion, the effect of gypsum is not distinct.

Monitoring of concrete curing using the electromechanical impedance technique: review and path forward

2019 ◽  
pp. 147592171989306 ◽  
Author(s):  
Yee Yan Lim ◽  
Scott T Smith ◽  
Ricardo Vasquez Padilla ◽  
Chee Kiong Soh
Keyword(s):  
State Of The Art ◽  
Research Field ◽  
Strength Development ◽  
Early Age ◽  
Remote Monitoring System ◽  
Electromechanical Impedance ◽  
Wide Range ◽  
Impedance Technique ◽  
Technology Modeling ◽  
Early Age Concrete

The ability to monitor the strength development of early-age concrete is an important capability in the laboratory and in the field. Accurate and reliable in situ measurements can inform the appropriate time for removal of formwork and loading of structural elements, as well as determination of batch quality. The piezoelectric-based electromechanical impedance technique is emerging as a viable option for such monitoring needs. The first research articles on the topic started to appear in 2005, and since then, the research field has advanced and has grown in popularity. This article therefore presents the first state-of-the-art review of the topic to date. In this article, existing research is reviewed and sorted into key themes while critical developments as well as knowledge gaps are identified. The topics addressed range from miniaturization of hardware, methods of installation, incorporation of wireless technology, modeling, data interpretation, signal processing, influence of curing, and environmental conditions to a wide range of other practical issues. Previous studies have indicated that the electromechanical impedance technique has the potential to be developed into an autonomous and remote monitoring system, capable of predicting the strength development of early-age concrete structures in real time. An end game is therefore the realization of this capability. Appropriate comments are therefore also provided in this article about this goal. Researchers interested in venturing into this research area shall find this article a useful introduction as well as a state-of-the-art assessment. In addition, the identified research gaps can inform projects for more experienced research teams.

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