Anton Tanasoglo
Optimal design solutions of double-circuit corner dead-end supports of overhead power transmission lines 110 kV
Donbas National Academy of Civil Engineering and Architecture
Abstract.The optimal design procedure of overhead power transmission lines’ (OPTL) supports caused by a modern state in the optimization field of steel structures, has been given. Improved search algorithm of the optimal parameters taking into account received dependences for effective lengths and longitudinal bending coefficients realized in the software package «MISI1», developed at the DNACEA, has been shown. It has been paid attention to the changes, entered in limits and conditions that are satisfied by the vector of variable parameters in order to find the geometric dimensions of minimal weight lattice structures. It has been given the schemes of the optimized double-circuit OPTL supports 110 kV corresponding to the climatic conditions of the Ukraine. There was made a comparative analysis of the masses of typical and optimal corner dead-end supports U110-2 with zinc coating and without it. Results of researches have been introduced at manufacturing, installation and operation of optimal tower support U110-2+14 on the territory of the Poltava mountain-concentrating industrial complex in Komsomolsk.
Keywords: optimal designing, overhead power transmission line, corner dead-end support, software package, objective function, algorithm.
Evgeny Romasyuk, Mixail Pakter, Valery Bratchun, Aleksandr Stukalov
The fatigue life of the modified asphalt concrete under dynamic loading
Donbas National Academy of Civil Engineering and Architecture
Abstract. It has been found out that when different test temperatures fatigue life of asphalt with a complex-modified structure is much higher as compared with conventional asphalt concrete. Increasing the fatigue life in 1.5–2.0 times has been observed in asphalt concrete system «bitumen modified with 2.0 % by weight glycidyl acrylate ethylene-brand Elvaloy-AM + 0.2 % PFC-105 – mineral material, 0.7 % by weight activated Elvaloy AM» and 1.1–1.5 times in the complex – modified asphalt concrete cast «bitumen modified with 2.0 % by weight methyl styrene butadiene rubber SKMS-30 + 30 % technical sulfur – mineral powder, 0.5 % by weight activated SKMS-30». According to the formula of A. V. Rudenskii, coefficients of fatigue life for each type of asphalt concrete were calculated. Asphalt concrete with a complex – modified structure are 1.1–1.4 times smaller values of m, which testifies to their higher fatigue life. The change in the number of cycles to failure, depending on the period of «rest» (discharge) of the sample during the test transient cyclic loads has been considered. The relationship between stress in the fine-grained asphalt concrete type «B» and asphaltic concrete with a complex-modified structure Elvaloy-AM strain deformation at a frequency of 0.5 Hz and a temperature of 20 °C has been carried out.
Keywords:oil road bitumen, asphalt mix, asphalt road, the fatigue life of asphalt concrete.
Vitaly Bespalov
Bitumenpolymer binder and polymerconcreteasphalt modified elvaloy am and styrenebutadiene rubber SKMS-30
Donbas National Academy of Civil Engineering and Architecture
Abstract. It is shown that the rational way to improve the durability of asphalt concrete is a modification of bitumen with polymers of different origin and surface activation of the mineral materials oligomers and polymers. The work carried out modification of the oil bitumen 60/90, while the two modifiers: methylstyrenebutadiene rubber SKMS-30 and ethyleneglycidylacrylate (Elvaloy AM). It was found that the optimal concentration of polymer in bitumen should be: 60/90+2 % by weight Elvaloy AM thermostating at 4 hours and 0.5–1.0 % by weight SKMS-30, and further increase the concentration SKMS-30 reduces adhesion bitumenpolymer binder to mineral materials. The use of two polymers: methyl styrene butadiene rubber SKMS-30 and ethyleneglycidylacrylate (Elvaloy AM) for the modification of binders improves the technological properties of organic binders and performance indicators of quality of asphalt polymer concretes.
Keywords: asphalt polymer concrete, road oil bitumen, mineral material, ethyleneglycidylacrylate, methylstyrenebutadiene rubber, bitumenpolymer binder.
Mykola Zaichenkoa, Alexander Serduka, Antonina Nazarovab, Marshdi Sahib Qosai Radib
Optimization of self-compacting cement road concrete on the criteria of the mobility of the mixture and compressive strength
aDonbas National Academy of Civil Engineering and Architecture, bLugansk National Agrarian University
Abstract. Application of self-compacting concrete (SCC) in road construction provides improved quality of the road pavement, increased speed of construction, reduced energy consumption and laboriousness of the process. However, it is necessary to solve the conflicting rather complicated task – to provide high mobility (self-compactness) of concrete mix during the molding process, on the other hand – to provide the ability to retain the shape of fresh concrete without sedimentation immediately after extrusion of the slip-former (the thixotropic effect). The optimization of the formulation of SCC on the water-cement ratio value as well as the content of fine additive in the form of milled limestone (ML) has been done. To ensure the mobility of the concrete mix according to the data of spread diameter of standard cone within 310–370 mm and the concrete compressive strength not less than 55 MPa, the region of optimum formulations has to be in the range of: (W/C=0.449–0.425); (ML=15–33 %).
Keywords: self-compacting concrete, optimization of the formulation, slump flow, compressive strength, regression equation.