Possibilities of Experimental Determinations of the Modulus of Elasticity in the early Stage of Ageing of Cement Composites

2018 ◽  
Vol 276 ◽  
pp. 35-40
Author(s):  
Romana Halamová ◽  
Dalibor Kocáb ◽  
Barbara Kucharczyková ◽  
Petr Daněk ◽  
Petr Misák
Keyword(s):  
Modulus Of Elasticity ◽  
Early Stage ◽  
Resonance Method ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Load Test ◽  
Cement Composites ◽  
Static Load Test

This paper deals with the possibilities of experimental determination of the dynamic and static modulus of elasticity of fine-grained cement composites in the early stage of setting and hardening - up to 72 hours. Several cement pastes and cement mortars were produced for the purpose of this experiment. The measurement of the modulus of elasticity on the manufactured cement-based composites was carried out in the first 24 hours, each time only by the ultrasonic pulse velocity test using the innovative Vikasonic instrument. In the following 48 hours, the resonance method and the static load test were employed. The results of the pilot measurement and particularly the assessment of the possibilities of determination of the moduli of elasticity are presented in this paper.

scholarly journals Determination of the static modulus of elasticity of cement mortars in the early stage of ageing

2020 ◽  
Vol 310 ◽  
pp. 00029
Author(s):  
Dalibor Kocab ◽  
Romana Halamová ◽  
Barbara Kucharczyková
Keyword(s):  
Modulus Of Elasticity ◽  
Early Stage ◽  
Ultrasonic Pulse Velocity ◽  
Cementitious Materials ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Static Modulus ◽  
Cement Mortars ◽  
The Moment ◽  
Static Modulus Of Elasticity

The paper deals with the influence of the composition of cementitious materials on the development of their modulus of elasticity in the early stage of ageing. The primary goal of the paper is to determine the static modulus of elasticity of cement mortars almost from the beginning of their setting. Four cement mortars were produced for the experiment. They differed only in the water/cement ratio and in the amount of plasticizer. All mortars were subjected to continuous measurement of the dynamic modulus of elasticity for 24 hours from the moment of their pouring into the moulds. The measurement involved the ultrasonic pulse velocity method. In addition, the static modulus of elasticity was determined at the mortar age of 24 hours. The results are presented in table and graphical forms.

Non-Destructive Testing for Concrete: Dynamic Modulus and Ultrasonic Velocity Measurements

2011 ◽  
Vol 243-249 ◽  
pp. 165-169 ◽  
Author(s):  
Iqbal Khan Mohammad
Keyword(s):  
Compressive Strength ◽  
Modulus Of Elasticity ◽  
Dynamic Modulus ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Dynamic Modulus Of Elasticity ◽  
Non Destructive

Nondestructive testing (NDT) is a technique to determine the integrity of a material, component or structure. The commonly NDT methods used for the concrete are dynamic modulus of elasticity and ultrasonic pulse velocity. The dynamic modulus of elasticity of concrete is related to the structural stiffness and deformation process of concrete structures, and is highly sensitive to the cracking. The velocity of ultrasonic pulses travelling in a solid material depends on the density and elastic properties of that material. Non-destructive testing namely, dynamic modulus of elasticity and ultrasonic pulse velocity was measured for high strength concrete incorporating cementitious composites. Results of dynamic modulus of elasticity and ultrasonic pulse velocity are reported and their relationships with compressive strength are presented. It has been found that NDT is reasonably good and reliable tool to measure the property of concrete which also gives the fair indication of the compressive strength development.

scholarly journals A Study on Initial Setting and Modulus of Elasticity of AAM Mortar Mixed with CSA Expansive Additive Using Ultrasonic Pulse Velocity

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4432
Author(s):  
Gum-Sung Ryu ◽  
Sung Choi ◽  
Kyung-Taek Koh ◽  
Gi-Hong Ahn ◽  
Hyeong-Yeol Kim ◽  
...  
Keyword(s):  
Modulus Of Elasticity ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Static Modulus ◽  
Setting Times ◽  
Initial Setting ◽  
Expansive Additive ◽  
Static Modulus Of Elasticity ◽  
Initial Reactivity

This study investigated the hardening process of alkali-activated material (AAM) mortar using calcium sulfoalumiante (CSA) expansive additive (CSA EA), which accelerates the initial reactivity of AAMs, and subsequent changes in ultrasonic pulse velocity (UPV). After the AAM mortar was mixed with three different contents of CSA EA, the setting and modulus of elasticity of the mortar at one day of age, which represent curing steps, were measured. In addition, UPV was used to analyze each curing step. The initial and final setting times of the AAM mortar could be predicted by analyzing the UPV results measured for 14 h. In addition, the dynamic modulus of elasticity calculated using the UPV results for 24 h showed a tendency similar to that of the static modulus of elasticity. The test results showed that the use of CSA EA accelerated the setting of the AAM mortar and increased the modulus of elasticity, and these results could be inferred using UPV. The proposed measurement method can be effective in evaluating the properties of a material that accelerates the initial reactivity.

SYNTHESIS AND CHARACTERIZATION OF SELF-HEALING MORTAR WITH MODIFIED STRENGTH

2015 ◽  
Vol 76 (1) ◽  
Author(s):  
Gassan Fahim Huseien ◽  
Jahangir Mirza ◽  
Nur Farhayu Ariffin ◽  
Mohd Warid Hussin
Keyword(s):  
Early Stage ◽  
Polymeric Materials ◽  
Building Blocks ◽  
Ultrasonic Pulse Velocity ◽  
Cementitious Materials ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Diglycidyl Ether ◽  
Self Healing ◽  
Research Initiative

Cementitious materials being the most prospective building blocks achieving their absolute strength to avoid the deterioration in the early stage of service life is ever-demanding. Minimizing the labor and capital-intensive maintenance and repair cost is a critical challenge. Thus, self-healing mortars with modified strength are proposed. Lately, self-healing of micro-cracks by introducing bacteria during the formation of mortar or concrete became attractive. Self-healing with polymeric admixtures is considered to be relatively more durable and faster process. Certainly, the self-healing of synthetic polymeric materials is inspired by biological systems, where the damage triggers an autonomic healing response. This emerging and fascinating research initiative may significantly improve the durability and the safety limit of the polymeric components potential for assorted applications. In this work, using epoxy resin (diglycidyl ether of bisphenol A) without any hardener as admixture polymeric-cementitious materials is prepared. These epoxy-modified mortars are synthesized with various polymer-cement ratios subjected to initial wet/dry curing (WDC) together with long term dry curing (DC). Their self-healing function and hardening effects are evaluated via preloading and drying of the specimens, chemical analysis, and ultrasonic pulse velocity testing. It is demonstrated that 10% of polymer is the best proportion for polymer-cement ratio. Furthermore, the wet/dry curing is established to be superior process for healing hairline cracks present in the mortar. The excellent features of the results suggest that our novel method may constitute a basis for improving the compressive strength and self-healing features of mortars.    

Influence of a Shrinkage-Reducing Admixture on the Damage to the Internal Structure of Alkali-Activated Composites during Testing of the Modulus of Elasticity

2018 ◽  
Vol 272 ◽  
pp. 28-33
Author(s):  
Dalibor Kocáb ◽  
Vlastimil Bílek Jr. ◽  
Libor Topolář ◽  
Petr Daněk ◽  
Barbara Kucharczyková ◽  
...  
Keyword(s):  
Internal Structure ◽  
Modulus Of Elasticity ◽  
Resonance Method ◽  
Ultrasonic Pulse Velocity ◽  
Pulse Velocity ◽  
Acoustic Activity ◽  
Static Modulus ◽  
Shrinkage Reducing Admixture ◽  
Static Modulus Of Elasticity ◽  
Alkali Activated

This article deals with an experimental determination of the static modulus of elasticity in compression on fine-grained composites based on alkali-activated slag. This experiment included an alkali-activated composite without a shrinkage-reducing admixture and the same composite with a shrinkage-reducing admixture. The test specimens were subjected to testing of the dynamic modulus of elasticity using the ultrasonic pulse velocity test and the resonance method as well as of the static modulus of elasticity in compression. The static modulus of elasticity test was accompanied by the measurement of the acoustic activity of the material using the acoustic emission method, whose advantages is the possibility to detect early formation and propagation of cracks in the internal structure of the material. The output of the described experiment is a detailed evaluation of the differences in the behaviour of the tested alkali-activated composites based on the observed values of the modulus of elasticity and the recorded acoustic activity of the material during loading.

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