The Effect of Technological Damage on the Properties and Reliability of Construction Materials and Structures

Dorofeev, Vitaliy; Myronenko, Igor; Pushkar, Natalia

doi:10.4028/p-lm1g4w

Cited by 8 publications

(3 citation statements)

References 10 publications

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“…The use of the dispersed mineral additives in the composition of concrete allows to reduce the cement consumption without compromising its quality, to control the kinetics and degree of the cement minerals hydration; as a result of chemical interaction of additives with hydration products to obtain the qualitatively new compounds and structures [1].…”

Section: Introductionmentioning

confidence: 99%

Structural Formation of the Cement Pastes Based on the Concrete Modified Dispersed Mineral Components

Khalyushev

Стельмах

Shcherban’

et al. 2020

MSF

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With the increase in the number of finely dispersed mineral additives in concrete, their water demand increases and the effect of micro-filling weakens. To solve this problem, various methods of dry surface modification are proposed. As a result of the finely dispersed mineral powders’ surface modification, an improvement in their rheological characteristics, a decrease in wettability, a change in granulometry and other properties are achieved. This article discusses the surface modification effect’s laws in a high-voltage electric field on the autogenous properties of mineral dispersed concrete components, structure formation processes, mechanical properties, and cement stone hydration products. According to the results of the study, it was found that the surface modification of bulk materials - concrete components - in a high-voltage electric field changes autohesion properties in comparison with control samples. The data indicate lower values of bulk density and angle of repose. This is due to a change in the balance of forces that arise during the mutual contact of particles after surface modification. With a certain balance of these forces, autohesion will contribute to the dense packing of particles and thereby affect the structure formation processes. The results of changes in the plastic strength of cement pastes confirm that there is an intensification of the structure formation process. Moreover, a more intense increase in plastic strength is observed during bipolar charging of particles in comparison with unipolar charging. This is due to an increase in the number of heterogeneous charges in the system and, as a consequence, an increase in the strength of adhesive contacts, as evidenced by the data of X-ray phase analysis.

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Section: Introductionmentioning

confidence: 99%

Structural Formation of the Cement Pastes Based on the Concrete Modified Dispersed Mineral Components

Khalyushev

Стельмах

Shcherban’

et al. 2020

MSF

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“…The dispersed mineral additives' use in the concrete composition allows to reduce the cement consumption without compromising its quality, to control the kinetics and the cement minerals hydration degree; as a result of the additives' chemical interaction with the hydration products to obtain the qualitatively new compounds and structures [1]. Moreover, the additives in the composition of composite cements can have various effects on concrete mixtures and concretes: increase or decrease in water demand; increase the water holding capacity of the concrete mixtures; the heat reduction during concrete hardening, shrinkage deformation; increased crack resistance of concrete, adhesion of concrete to reinforcement; acceleration of cement hydration during steaming; increasing frost resistance of concrete or its reduction; increase sulfate and acid resistance of concrete [2].…”

Section: Introductionmentioning

confidence: 99%

The Activation Technology for the Surface Modification High Voltage Electric Field Dispersed Mineral Additives for Concrete

Khalyushev

Mayilyan

Стельмах

et al. 2020

MSF

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The aim of the research was to study the activation technology of the materials for concrete by their surface modification in a high-voltage electric field. It is noted that the mineral additives modified in a high-voltage electric field are characterized by a higher activity of the calcium hydroxide absorption. It was established that, despite the presence of a large number of crystalline compounds in metakaolin, its pozzolanic activity in the absorption of calcium hydroxide from a saturated solution is quite high. The same value of the hydration activity coefficient is also determined for the ground slag. The authors found that a characteristic feature of the dispersed mineral additives, surface-modified in a high-voltage electric field in comparison with control samples, are the lower values of bulk density and repose angle. This is due to a change in the forces balance that occurs during the mutual contact of particles. The influence of the mineral additives’ surface modification in a high-voltage electric field on interparticle interactions in the “solid – liquid” system is evaluated. It is established that in the absence of a repulsion barrier, the particles form the aggregates that increase their sedimentation rate. During unipolar or bipolar charging of particles in an electric field, the sedimentation rate slows down or accelerates accordingly. These effects are used to modify the cement surface.

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“…Therefore, the change of the initial structural organization under the influence of various types of activation should lead to a change the conditions of inter-cluster interfaces origin and the ways of their development to technological cracks and inner surfaces of partition. This can be quantified through the coefficient of technological damage as an indirect characteristic of structural transformations of filled polymer compositions, which is expressed as the ratio Kd=∑Li/L1 (∑Li is the actual length of fracture crack, mm/mm; L1 is geodesic line length AB as the shortest distance between the exit points of fracture crack to a side surfaces of sample), mm/mm [9].…”

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confidence: 99%

Role of Activation in Formation of Polymer Composite Properties

Kazmirchuk

Korobko

Semenova

et al. 2020

KEM

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The possibility of increasing crack resistance, strength and elastic modulus of polymer-containing compositions due to the directed organization of their structure by internal, external and complex activation is investigated. Filled polymer compositions are presented as open complex dynamic systems. This made it possible to use rational fillers and special matrix-transformer of external electromagnetic influences as factors for controlling the processes of their structure formation and hardening to obtain materials with the required properties.

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The Effect of Technological Damage on the Properties and Reliability of Construction Materials and Structures

Cited by 8 publications

References 10 publications

Structural Formation of the Cement Pastes Based on the Concrete Modified Dispersed Mineral Components

Structural Formation of the Cement Pastes Based on the Concrete Modified Dispersed Mineral Components

The Activation Technology for the Surface Modification High Voltage Electric Field Dispersed Mineral Additives for Concrete

Role of Activation in Formation of Polymer Composite Properties

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