scholarly journals Evaluation of Early-Age Concrete Compressive Strength with Ultrasonic Sensors

Sensors ◽  
2017 ◽  
Vol 17 (8) ◽  
pp. 1817 ◽  
Author(s):  
Hyejin Yoon ◽  
Young Kim ◽  
Hee Kim ◽  
Jun Kang ◽  
Hyun-Moo Koh
Keyword(s):  
Compressive Strength ◽  
Early Age ◽  
Concrete Compressive Strength ◽  
Ultrasonic Sensors ◽  
Early Age Concrete

scholarly journals Experimental Study to Determine the Failure Criteria of Concrete at Its Early-Age

2015 ◽  
Vol 2015 ◽  
pp. 1-13
Author(s):  
Hongyan Ding ◽  
Lei Zhang ◽  
Puyang Zhang
Keyword(s):  
Compressive Strength ◽  
Constitutive Relation ◽  
Concrete Structures ◽  
Failure Criteria ◽  
Early Age ◽  
Construction Technique ◽  
Concrete Material ◽  
Axial Tensile ◽  
Mathematical Relation ◽  
Early Age Concrete

The failure criteria and the constitutive relation of materials for an early-age concrete are the most common reasons to conduct the nonlinear analysis and to assess the concrete structures during the construction stage. The delay of theoretical advancement in this field resulted into a mismatch between the rough theories and the advanced algorithms, which were adopted for the estimation and analysis of early-age concrete structures. It is often impossible to find an appropriate way to determine the failure criteria and its constitutive relation that may serve as a baseline. As a consequence, the development and the application of advanced techniques of construction, for example, early dismantling construction technique of formwork, have severely been restrained. Therefore, the study of the failure criteria and its constitutive relation of concrete materials at early-age are important. In this paper, the cubic compressive strength, the prismatic compressive strength, and the axial tensile strength are determined by carrying out a strength test on C20 concrete material at an early-age. Next, the failure criteria of C20 early-age concrete material in the octahedral stress space have been studied and analyzed by using the regression analysis and by deriving the mathematical relation.

Study of Properties of Sprayed Concrete Prepared in Laboratory

2014 ◽  
Vol 897 ◽  
pp. 234-237
Author(s):  
Adam Hubáček
Keyword(s):  
Compressive Strength ◽  
Concrete Strength ◽  
Physical Parameters ◽  
Early Age ◽  
Concrete Compressive Strength ◽  
Sprayed Concrete ◽  
Manufacture Process ◽  
Common Application ◽  
Common Laboratory

Sprayed concrete is widely applied in spite of developing economical crisis. The paper focuses on possibilities of manufacture and testing basic physical parameters of sprayed concrete prepared in common laboratory mixer and compacted by vibration combined with defined level of pressure. The aim is assessment of basic properties of sprayed concrete: compressive strength of early age sprayed concrete, strength of drilled core, assessment of homogeneity and density of concrete, determination of elasticity modules. On the basis of results, possible correlation relationships will be predicted for this manufacture process and for common application by means of spraying onto a structure.

scholarly journals Evaluation of Concrete Material Properties at Early Age

CivilEng ◽  
2020 ◽  
Vol 1 (3) ◽  
pp. 326-350
Author(s):  
Osamah Obayes ◽  
Emad Gad ◽  
Tilak Pokharel ◽  
Jessey Lee ◽  
Kamiran Abdouka
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Fracture Energy ◽  
Material Properties ◽  
Modulus Of Elasticity ◽  
Inverse Analysis ◽  
Splitting Tensile Strength ◽  
Early Age ◽  
Concrete Compressive Strength ◽  
The Relationship

This article investigates the development of the following material properties of concrete with time: compressive strength, tensile strength, modulus of elasticity, and fracture energy. These properties were determined at seven different hydration ages (18 h, 30 h, 48 h, 72 h, 7 days, 14 days, 28 days) for four pure cement concrete mixes totaling 336 specimens tested throughout the study. Experimental data obtained were used to assess the relationship of the above properties with the concrete compressive strength and how these relationships are affected with age. Further, this study investigates prediction models available in literature and recommendations are made for models that are found suitable for application to early age concrete. Results obtained indicate that the relationship between the splitting tensile strength and concrete compressive strength can be approximated with a power function between 0.7 and 0.8, and this correlation is not affected by age. Fracture energy of the concrete and modulus of elasticity values obtained in this study correlate well with the square root of the compressive strength and it was found that this relationship holds true for all hydration ages investigated in this paper. Inverse analysis on the wedge-splitting test was conducted to determine the direct tensile strength. Values of tensile strength obtained from the inverse analysis have been validated numerically by carrying out finite element analysis on the wedge split, and anchor pull-out tests. The ratio of the tensile strength obtained from the inverse analysis to the splitting tensile strength was found to be in the range of 0.5–0.9 and 0.7 on average.

Curing Strength Monitoring of Early-Age Concrete Based on Velocity of Guided Wave Using Embedded Plate-Type PZT Sensor Module

2013 ◽  
Vol 281 ◽  
pp. 645-648
Author(s):  
Ju Won Kim ◽  
Eun Seok Shin ◽  
Chang Gil Lee ◽  
Seung Hee Park ◽  
Seo Kinn Hong
Keyword(s):  
Compressive Strength ◽  
Wave Velocity ◽  
Steel Plate ◽  
Piezoelectric Sensor ◽  
Guided Wave ◽  
Early Age ◽  
Monitoring Method ◽  
Sensor Module ◽  
Early Age Concrete ◽  
Plate Type

In this study, a guided wave based nondestructive curing strength monitoring method is proposed to monitor the curing strength of the early-age concrete. This approach used the embedded steel plate-type PZT sensor module which was fabricated by bonding the two pieces of piezoelectric sensor to a steel plate. The steel plate provided the constant path for guided wave propagation and it protected the piezoelectric sensors from impacts and environmental variations. To measure the guided wave signals from the early-age concrete, fabricated sensor modules were landfilled at the same time with concrete placement.While the concrete was curing, guided wave signals were measured by pitch-catch method continuously at regular intervals. Wavelet transform process was performed to improve the quality of the signal by removing the signal’s noise of undesired frequencies. The TOF (Time of flight) of guidedwave was extract from de-noised signal using peak tracing algorithm to calculate the velocity of wave. The calculated wave velocity hysteresis according to the curing time was traced to analysis the pattern of variations of wave velocity. Finally, specific equations to estimate the strength of the concrete were derived using regression analysis based on the wave velocity and compressive strength from destructive compressive strength test.

scholarly journals Assessment of the early-age compressive strength of concrete

2021 ◽  
Vol 20 (2) ◽  
pp. 005-014
Author(s):  
Dorota Michałowska-Maziejuk ◽  
Barbara Goszczyńska
Keyword(s):  
Compressive Strength ◽  
Early Stage ◽  
Concrete Strength ◽  
Early Age ◽  
Concrete Compressive Strength ◽  
Strength Parameters ◽  
Eurocode 2 ◽  
Strength Tests ◽  
Compressive Strength Of Concrete

This paper analyses the results of concrete compressive strength tests on cubic samples with different w/c ratios during the early stage of hardening (at 7, 14, and 28 days). Statistical and strength parameters were assessed and the quality of the concrete was estimated. The expected concrete grade, C25/30, was confirmed against the formulation provided by the prefabrication plant. Then, the amount of individual constituents was adjusted to obtain the target grade of concrete, i.e., C20/25. The concrete grade was estimated based on concrete strength parameters measured at three time points and compared with the expected 28-day strength values determined as per Eurocode 2 and with the concrete grade defined by these values. The paper also provides an overview of the most widely used methods of testing concrete compressive strength.

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