Dynamic elastic modulus of cement paste at early age based on nondestructive test and multiscale prediction model

2014 ◽  
Vol 29 (2) ◽  
pp. 321-328 ◽  
Author(s):  
Haitao Zhao ◽  
Donghui Huang ◽  
Xiaojun Wang ◽  
Xudong Chen
Keyword(s):  
Elastic Modulus ◽  
Nondestructive Test ◽  
Prediction Model ◽  
Cement Paste ◽  
Dynamic Elastic Modulus ◽  
Early Age

Effect of Admixtures on Dynamic Elastic Modulus of Cement Paste at Early Age

2011 ◽  
Vol 261-263 ◽  
pp. 450-455
Author(s):  
Dong Hui Huang ◽  
Sheng Xing Wu ◽  
Xiao Jun Wang ◽  
Hai Tao Zhao
Keyword(s):  
Elastic Modulus ◽  
Cement Paste ◽  
Mechanical Response ◽  
Dynamic Elastic Modulus ◽  
Early Age ◽  
Concrete Technology ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Shrinkage Reducing Admixture ◽  
Nondestructive Testing Method

The elastic modulus of cement paste is the key parameter for characterizing the mechanical response of concrete. In modern concrete technology, the admixtures are often used to enhance the performance of concrete. This paper introduces a nondestructive testing method to evaluate the dynamic elastic modulus of cement paste. Moreover, the effect of water-cement ratio and conventional admixtures on the dynamic elastic modulus of cement paste is investigated, in which three kinds of admixtures are taken into account including Viscosity Modifying Admixture (VMA), Silica Fume (SF), and Shrinkage-Reducing Admixture (SRA). The results from experimental investigation indicate that the dynamic elastic modulus of cement paste increases with decreasing water-cement ratio. The addition of SF increases the dynamic elastic modulus, however, the overdosage of VMA causes its reduction. SRA reduces the elastic modulus at early age without affecting the elastic modulus at later period.

scholarly journals Establishing a dynamic elastic modulus prediction model of larch based on nondestructive testing data

BioResources ◽  
2020 ◽  
Vol 15 (3) ◽  
pp. 4835-4850
Author(s):  
Liting Cheng ◽  
Wei Wang ◽  
Zhiguo Yang ◽  
Jian Dai
Keyword(s):  
Elastic Modulus ◽  
Nondestructive Testing ◽  
Prediction Model ◽  
Information Diffusion ◽  
Dynamic Elastic Modulus ◽  
Coefficient Of Determination ◽  
Diffusion Method ◽  
Strong Basis ◽  
Evaluation Indexes ◽  
Testing Data

To accurately evaluate the dynamic elastic modulus (Ed) of wood in ancient timberwork buildings, the new materials of larch were used as the research object, and the stress wave nondestructive testing method was used to determine it. Based on nondestructive testing data, this paper proposed a method for predicting the Ed of larch using the principle of information diffusion. It selected the distance (D) from the bark to the pith in the cross-section of the wood and the height (H) from the base to the top in the radial section of the wood. The fuzzy diffusion relationships between the two evaluation indexes and the Ed were established using the information diffusion principle and the first- and second-order fuzzy approximate inferences in the fuzzy information optimization process. The calculation results showed that the dynamic elastic modulus model constructed by the information diffusion method can better predict the Ed of larch. The coefficient of determination between the measured value and the predicted value of the Ed was 0.861, they were in good agreement. The weights of the two influencing factors were 0.7 and 0.3, respectively, the average relative error of the fitted sample data was the minimum, which was 8.55%. This prediction model provided a strong basis for field inspection.

Calculation of elastic modulus of early-age cement paste

2012 ◽  
Vol 24 (4) ◽  
pp. 193-201 ◽  
Author(s):  
Lei Jiang ◽  
Yamei Zhang ◽  
Chuanlin Hu ◽  
Zongjin Li
Keyword(s):  
Elastic Modulus ◽  
Cement Paste ◽  
Early Age

Comparison of water removal methods from cement paste at early age

2021 ◽  
Author(s):  
Lenka Scheinherrová ◽  
Vojtěch Pommer ◽  
Eva Vejmelková ◽  
Robert Černý
Keyword(s):  
Cement Paste ◽  
Early Age ◽  
Water Removal

scholarly journals Mechanical and Microstructural Characteristics of Calcium Sulfoaluminate Cement Exposed to Early-Age Carbonation Curing

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3515
Author(s):  
Weikang Wang ◽  
Xuanchun Wei ◽  
Xinhua Cai ◽  
Hongyang Deng ◽  
Bokang Li
Keyword(s):  
Cement Paste ◽  
Pore Diameter ◽  
Performance Enhancement ◽  
Diameter Distribution ◽  
Early Age ◽  
Calcium Sulfoaluminate ◽  
Starting Point ◽  
And Performance ◽  
Curing Pressure ◽  
Carbonation Curing

: The early-age carbonation curing technique is an effective way to improve the performance of cement-based materials and reduce their carbon footprint. This work investigates the early mechanical properties and microstructure of calcium sulfoaluminate (CSA) cement specimens under early-age carbonation curing, considering five factors: briquetting pressure, water–binder (w/b) ratio, starting point of carbonation curing, carbonation curing time, and carbonation curing pressure. The carbonization process and performance enhancement mechanism of CSA cement are analyzed by mercury intrusion porosimetry (MIP), thermogravimetry and derivative thermogravimetry (TG-DTG) analysis, X-ray diffraction (XRD), and scanning electron microscope (SEM). The results show that early-age carbonation curing can accelerate the hardening speed of CSA cement paste, reduce the cumulative porosity of the cement paste, refine the pore diameter distribution, and make the pore diameter distribution more uniform, thus greatly improving the early compressive strength of the paste. The most favorable w/b ratio for the carbonization reaction of CSA cement paste is between 0.15 and 0.2; the most suitable carbonation curing starting time point is 4 h after initial hydration; the carbonation curing pressure should be between 3 and 4 bar; and the most appropriate time for carbonation curing is between 6 and 12 h.

Studies the Properties of Polyaspartic Polyurea Coated Concrete under Coaction of Salt Fog and Freeze-Thaw

2012 ◽  
Vol 455-456 ◽  
pp. 781-785
Author(s):  
Ping Lu ◽  
Xin Mao Li ◽  
Xue Qiang Ma ◽  
Wei Bo Huang
Keyword(s):  
Elastic Modulus ◽  
Frost Resistance ◽  
Dynamic Elastic Modulus ◽  
Freeze Thaw ◽  
Decrease Rate ◽  
Thaw Cycle ◽  
Freeze Thaw Cycle ◽  
Salt Fog

. This paper mainly studied the properties of PAE polyurea coated concrete under coactions of salt fog and freeze-thaw. After exposed salt fog conditions for 200d, T3, B2, F2 and TM four coated concrete relative dynamic elastic modulus have small changes, but different coated concrete variation amplitude is different. T3 coated concrete after 100 times of freeze-thaw cycle the relative dynamic elastic modulus began to drop, 200 times freeze-thaw cycle ends, relative dynamic elastic modulus variation is the largest, decrease rate is 95%, TM concrete during 200 times freeze-thaw cycle, relative dynamic elastic modulus almost no change, B2 concrete and F2 concrete the extent of change between coating T3 and TM. After 300 times the freeze-thaw cycle coated concrete didn't appear freeze-thaw damage phenomenon. Four kinds of coating concrete relative dynamic elastic modulus variation by large to small order: T3 coated concrete > B2 coated concrete >F2 coated concrete > TM coated concrete, concrete with the same 200d rule. Frost resistance order, by contrast, TM coated concrete > B2 coated concrete > F2 coated concrete > T3 coated concrete.

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