Mechanism for using piezoelectric sensor to monitor strength gain process of cementitious materials with the temperature effect

2020 ◽  
pp. 1045389X2097444
Author(s):  
Guangshuai Han ◽  
Yen-Fang Su ◽  
Tommy Nantung ◽  
Na Lu
Keyword(s):  
Mechanical Properties ◽  
Temperature Effect ◽  
Temperature Compensation ◽  
Piezoelectric Sensor ◽  
Cementitious Materials ◽  
Strength Gain ◽  
Electromechanical Impedance ◽  
Sensing System ◽  
Compensation Technique ◽  
Estimation System

Recently, the piezoelectric based sensor coupled with electromechanical impedance (EMI) technique is gaining attention on monitoring the mechanical properties changes in cementitious materials. However, the EMI signals obtained from the sensing system are not only influenced by the development of inherent mechanical properties in the host structure but also affected by the variation of temperature. When implementing a piezoelectric based sensor, both the ambient temperature change and the heat release from newly casted concrete would influence the sensing accuracy. In order to eliminate the biases from temperature effect, the mechanisms of EMI technique for strength sensing were investigated. The experiment work was separated in two parts. The piezoelectric sensors were first used to monitor the strength gaining of the newly casted cementitious samples curing under constant temperature. A strength estimation system was developed based on the experiment results. Later, the temperature variation was induced to affect the sensing performance. A temperature compensation technique was proposed to eliminate the temperature effect. It has concluded that the proposed compensation method can improve the strength sensing accuracy. The new understanding should help to promote the practical applicable EMI sensing technique.

A statistical analysis of temperature compensation for piezoelectric sensor bonded to AISI-1080 material

2020 ◽  
pp. 095440622097825
Author(s):  
Mesut Tekkalmaz ◽  
Gökhan Haydarlar ◽  
M Alper Sofuoğlu
Keyword(s):  
Environmental Conditions ◽  
Temperature Compensation ◽  
Statistical Tests ◽  
Piezoelectric Sensor ◽  
Test Results ◽  
Effective Frequency ◽  
Frequency Shifts ◽  
Electromechanical Impedance ◽  
Compensation Process ◽  
The Right

Electromechanical impedance (EMI) method has been widely used to evaluate structural health in recent years. In this method inexpensive, small, easy to apply, lightweight piezoelectric sensors are used to observe the changes in the structures. Different environmental conditions affect the piezoelectric sensor and the structure significantly. If the environmental impact is neglected, it causes misinterpretations as if it were present, although there is no construction defect. Therefore, it is necessary to compensate for the environmental effect. In this study, the EMI method was performed for AISI 1080 specimen at different environmental conditions. Impedance measurements were carried out between –45°C and –10°C. It has been observed that as the temperature decreases, the frequency shifts to the right and the amplitude increases. Temperature compensation was carried out to prevent these shifts. RMSD, MAPD, and CCDM were used as damage metrics. The effective frequency shift (EFS) algorithm was applied, and temperature compensation was performed according to the CCDM. As a result, damage metric values decrease after temperature compensation. Considering the change of damage metric values as a result of the compensation process, CCDM is a useful metric to detect changes. In the final stage, statistical tests (Pearson/Spearman and paired t-tests) were performed to compare non-compensated/compensated test results. Generally, damage metrics produce successful results in terms of statistical tests.

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.

scholarly journals An Overview on the Rheology, Mechanical Properties, Durability, 3D Printing, and Microstructural Performance of Nanomaterials in Cementitious Composites

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2950
Author(s):  
Hongwei Song ◽  
Xinle Li
Keyword(s):  
Mechanical Properties ◽  
3D Printing ◽  
Three Dimensional ◽  
Cementitious Materials ◽  
Research Area ◽  
Cementitious Composites ◽  
Split Tensile Strength ◽  
Contour Crafting ◽  
Wide Range ◽  
Active Research

The most active research area is nanotechnology in cementitious composites, which has a wide range of applications and has achieved popularity over the last three decades. Nanoparticles (NPs) have emerged as possible materials to be used in the field of civil engineering. Previous research has concentrated on evaluating the effect of different NPs in cementitious materials to alter material characteristics. In order to provide a broad understanding of how nanomaterials (NMs) can be used, this paper critically evaluates previous research on the influence of rheology, mechanical properties, durability, 3D printing, and microstructural performance on cementitious materials. The flow properties of fresh cementitious composites can be measured using rheology and slump. Mechanical properties such as compressive, flexural, and split tensile strength reveal hardened properties. The necessary tests for determining a NM’s durability in concrete are shrinkage, pore structure and porosity, and permeability. The advent of modern 3D printing technologies is suitable for structural printing, such as contour crafting and binder jetting. Three-dimensional (3D) printing has opened up new avenues for the building and construction industry to become more digital. Regardless of the material science, a range of problems must be tackled, including developing smart cementitious composites suitable for 3D structural printing. According to the scanning electron microscopy results, the addition of NMs to cementitious materials results in a denser and improved microstructure with more hydration products. This paper provides valuable information and details about the rheology, mechanical properties, durability, 3D printing, and microstructural performance of cementitious materials with NMs and encourages further research.

scholarly journals Temperature Effect on the Mechanical Properties of Electrospun PU Nanofibers

2018 ◽  
Vol 13 (1) ◽  
Author(s):  
Ji Zhou ◽  
Qing Cai ◽  
Xing Liu ◽  
Yanhuai Ding ◽  
Fu Xu
Keyword(s):  
Mechanical Properties ◽  
Temperature Effect

scholarly journals Numerical Studies of the Effects of Water Capsules on Self-Healing Efficiency and Mechanical Properties in Cementitious Materials

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Haoliang Huang ◽  
Guang Ye
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Elastic Modulus ◽  
Cementitious Materials ◽  
Self Healing ◽  
Negative Effects ◽  
Numerical Studies ◽  
Healing Efficiency ◽  
The Impact ◽  
Positive Effect

In this research, self-healing due to further hydration of unhydrated cement particles is taken as an example for investigating the effects of capsules on the self-healing efficiency and mechanical properties of cementitious materials. The efficiency of supply of water by using capsules as a function of capsule dosages and sizes was determined numerically. By knowing the amount of water supplied via capsules, the efficiency of self-healing due to further hydration of unhydrated cement was quantified. In addition, the impact of capsules on mechanical properties was investigated numerically. The amount of released water increases with the dosage of capsules at different slops as the size of capsules varies. Concerning the best efficiency of self-healing, the optimizing size of capsules is 6.5 mm for capsule dosages of 3%, 5%, and 7%, respectively. Both elastic modulus and tensile strength of cementitious materials decrease with the increase of capsule. The decreasing tendency of tensile strength is larger than that of elastic modulus. However, it was found that the increase of positive effect (the capacity of inducing self-healing) of capsules is larger than that of negative effects (decreasing mechanical properties) when the dosage of capsules increases.

scholarly journals Effects of Nano-CaCO3/Limestone Composite Particles on the Hydration Products and Pore Structure of Cementitious Materials

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Huashan Yang ◽  
Yujun Che
Keyword(s):  
Mechanical Properties ◽  
Pore Structure ◽  
Reaction System ◽  
Cementitious Materials ◽  
Limestone Powder ◽  
Composite Particles ◽  
Gravimetric Analysis ◽  
Hydration Products ◽  
Scanning Calorimetry ◽  
Necked Flask

The agglomeration of nano-CaCO3 (NC) is the largest bottleneck in applications in cementitious materials. If nano-CaCO3 modifies the surface of micron-scale limestone powder (LS), then it will form nano-CaCO3/limestone composite particles (NC/LS). It is known that micron-scale limestone is easily dispersed, and the “dispersion” of NC is governed by that of LS. Therefore, the dispersion of nano-CaCO3 can be improved by the NC/LS in cementitious materials. In this work, the preparation of NC/LS was carried out in a three-necked flask using the Ca(OH)2-H2O-CO2 reaction system. The morphology of NC/LS was observed by a field emission scanning electron microscope (FE-SEM). The effects of NC/LS on the hydration products and pore structure of cementitious materials are proposed. 5% NC/LS was added into cement paste and mortar, and the mechanical properties of the specimens were measured at a certain age. Differential scanning calorimetry (DSC), thermal gravimetric analysis (TG), and backscattered electron imaging (BSE) were conducted on the specimens to investigate the hydration products and pore structure. The properties of specimens with NC/LS were compared to that of control specimens (without NC/LS). The results revealed that NC/LS reduced the porosity and improved the mechanical properties of the cementitious materials.

Temperature effect on the mechanical properties of carbon, glass and carbon–glass FRP laminates

2015 ◽  
Vol 75 ◽  
pp. 342-348 ◽  
Author(s):  
Rami A. Hawileh ◽  
Adi Abu-Obeidah ◽  
Jamal A. Abdalla ◽  
Adil Al-Tamimi
Keyword(s):  
Mechanical Properties ◽  
Temperature Effect ◽  
Glass Frp

Experimental Investigation on Improving Electromechanical Impedance Based Damage Detection by Temperature Compensation

2013 ◽  
Vol 569-570 ◽  
pp. 1132-1139 ◽  
Author(s):  
Thomas Siebel ◽  
Mihail Lilov
Keyword(s):  
Damage Detection ◽  
Structural Damage ◽  
Temperature Compensation ◽  
Impact Damage ◽  
Correlation Coefficients ◽  
Electromechanical Impedance ◽  
Reinforced Plastic ◽  
Influence Of Temperature On ◽  
Compensation Approach ◽  
The Impact

The sensitivity of the electromechanical impedance to structural damage under varying temperature is investigated in this paper. An approach based on maximizing cross-correlation coefficients is used to compensate temperature effects. The experiments are carried out on an air plane conform carbon fiber reinforced plastic (CFRP) panel (500mm x 500mm x 5mm) instrumented with 26 piezoelectric transducers of two different sizes. In a first step, the panel is stepwise subjected to temperatures between-50 °C and 100 °C. The influence of varying temperatures on the measured impedances and the capability of the temperature compensation approach are analyzed. Next, the sensitivity to a 200 J impact damage is analyzed and it is set in relation to the influence of a temperature change. It becomes apparent the impact of the transducer size and location on the quality of the damage detection. The results further indicate a significant influence of temperature on the measured spectra. However, applying the temperature compensation algorithm can reduce the temperature effect at the same time increasing the transducer sensitivity within its measuring area. The paper concludes with a discussion about the trade-off between the sensing area, where damage should be detected, and the temperature range, in which damage within this area can reliably be detected.

scholarly journals Review on the Influence of Temperature upon Hydrogen Effects in Structural Alloys

Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 423
Author(s):  
Thorsten Michler ◽  
Frank Schweizer ◽  
Ken Wackermann
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Temperature Effect ◽  
Statistical Approach ◽  
Austenitic Stainless Steels ◽  
Carbon Steels ◽  
Effect Of Temperature ◽  
Engineering Applications ◽  
Selection For ◽  
Typical Temperature

It is well-documented experimentally that the influence of hydrogen on the mechanical properties of structural alloys like austenitic stainless steels, nickel superalloys, and carbon steels strongly depends on temperature. A typical curve plotting any hydrogen-affected mechanical property as a function of temperature gives a temperature THE,max, where the degradation of this mechanical property reaches a maximum. Above and below this temperature, the degradation is less. Unfortunately, the underlying physico-mechanical mechanisms are not currently understood to the level of detail required to explain such temperature effects. Though this temperature effect is important to understand in the context of engineering applications, studies to explain or even predict the effect of temperature upon the mechanical properties of structural alloys could not be identified. The available experimental data are scattered significantly, and clear trends as a function of chemistry or microstructure are difficult to see. Reported values for THE,max are in the range of about 200–340 K, which covers the typical temperature range for the design of structural components of about 230–310 K (from −40 to +40 °C). That is, the value of THE,max itself, as well as the slope of the gradient, might affect the materials selection for a dedicated application. Given the current lack of scientific understanding, a statistical approach appears to be a suitable way to account for the temperature effect in engineering applications. This study reviews the effect of temperature upon hydrogen effects in structural alloys and proposes recommendations for test temperatures for gaseous hydrogen applications.

Research Progress on the Hydration of Portland Cement with Calcined Clay and Limestone

2021 ◽  
Vol 1036 ◽  
pp. 240-246
Author(s):  
Jin Tang ◽  
Su Hua Ma ◽  
Wei Feng Li ◽  
Hui Yang ◽  
Xiao Dong Shen
Keyword(s):  
Mechanical Properties ◽  
Portland Cement ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Research Progress ◽  
Hydration Reaction ◽  
Hydration Products ◽  
Early Hydration ◽  
Calcined Clay ◽  
Dense Microstructure

The use of calcined clay and limestone as supplementary cementitious materials, can have a certain influence on the hydration of Portland cement. This paper reviewed the influence of limestone and calcined clay and the mixture of limestone and calcined clay on the hydration of cement. Both limestone and calcined clay accelerate the hydration reaction in the early hydration age and enhance the properties of cement. Limestone reacts with C3A to form carboaluminate, which indirectly stabilized the presence of ettringite, while calcined clay consumed portlandite to form C-(A)-S-H gel, additional hydration products promote the densification of pore structure and increase the mechanical properties. The synergistic effect of calcined clay and limestone stabilize the existence of ettringite and stimulate the further formation of carboaluminate, as well as the C-(A)-S-H gel, contributed to a dense microstructure.

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