Papers by Trong-Chuc Nguyen
Periodica Polytechnica Civil Engineering
Industrial waste management has been an integral part of many countries in the world, including i... more Industrial waste management has been an integral part of many countries in the world, including in Vietnam. In which, bottom ash (BA) has been used as a pozzolanic additive in compositions of the heavy concrete applying for airport concrete pavement (ACP), which allows reducing the hydration heat, the cost, and the thermal cracking of the concrete during the construction process. The purpose of this study is to summarize the experimental laboratory results of the heavy concrete samples containing 35 % BA sourced from a thermal power plant in Vietnam. The mechanical and thermal properties of the heavy concrete samples were determined at different curing ages. Besides, the heat of cement hydration during the preparation of the heavy concrete in the laboratory was measured using a "TAM AIR" isothermal calorimeter. Moreover, the Midas civil computer software based on the finite element method was used to analyze the temperature field and thermal cracking index of the ACP at th...
The usage of monolithic concrete technology in massive structure construction has created a need ... more The usage of monolithic concrete technology in massive structure construction has created a need for a more detailed design focused on crack control. In this study, the American standard ACI 211.1-09 and absolute volume method were used to determine the composition of heavy weight concrete for the high-rise building foundation. The concrete block temperature behavior has been analyzed by a three-dimensional thermal model in program Midas Civil. The conducted studies' result provided the possibility of obtaining heavy weight concrete from Vietnam local raw materials regarding to the concrete mixture workability of 16 cm standard cone, compressive strength of 42.3 MPa and average tensile strength of 3.5 MPa at the age of 28 days. According to the model analysis results, the maximum temperatures of the massive concrete foundation at the first (after 72 hours) and second pour (after 144 hours) from the beginning of construction are respectively 55.7 0 C and 65.5 0 C. In addition, the temperature differences at the core of each concrete pours with respect to the concrete outer portion, which induces a risk of through cracking in structure body or surface were determined.
The benefits of using mineral additive as a partial replacement for cement in heavyweight concret... more The benefits of using mineral additive as a partial replacement for cement in heavyweight concrete are discussed. This paper presents the strength development and temperature distribution of concrete using Class F of natural pozzolan (PU) sourced from Northern part of Vietnam. Based on the results of conducted studies, strengths of the natural pozzolan concrete at different ages were generally lower than those of control concrete. The 7-day compressive strengths of concrete with 20% PU decreases mostly by 30.1% and least by 12.3% at the age of 28 days in comparison with control concrete. However, natural pozzolan increases the workability of fresh concrete up to 16.67% in comparison with control concrete. By using the computer program Midas Civil, the maximum temperatures at the center of concrete block with 100% cement and of concrete block with 80% cement + 20% PU are 65.76 0 С and 52.44 0 С, respectively, after 48 hours from the beginning of pouring. In addition, temperature difference between the central point and the environmental temperature of the control concrete are higher than heavyweight concrete using 20% PU. Meaningfully, the risk of through thermal cracking of heavyweight concrete without pozzolan are higher than heavyweight concrete PU to replace 20% of mass cement.
Москва 2018 УДК 621.8 + 628 + 69:059 ББК 39.9 Т38 Т38 Технологии в инженерно-экологическом строит... more Москва 2018 УДК 621.8 + 628 + 69:059 ББК 39.9 Т38 Т38 Технологии в инженерно-экологическом строительстве, механизации и жилищно-коммунальном комплексе [Электронный ресурс] : сборник докладов внутривузовской научно-технической конференции (г. Москва, 19-20 декабря 2017 г.) ; М-во образования и науки Рос. Федерации, Нац. исследоват. Моск. гос. строит. ун-т. -Электрон. дан. и прогр. (21,5 Мб). -Москва : Издательство МИСИ-МГСУ, 2018. -Режим доступа:
In construction of mass concrete dams the main effect on the structure are temperature impacts. H... more In construction of mass concrete dams the main effect on the structure are temperature impacts. Heat release in cement hydration and the effect of many factors may result in considerable temperature gradients and cracks. The most dangerous here is the zone near the structure contact with the foundation bed. This manuscript gives analysis of dependence of the temperature regime and thermally stressed state of the zone near the structure contact with the foundation bed on the operating factors, preparation of recommendations on optimization of the construction procedure. 1. Introduction The mass concrete structures most often are encountered in hydraulic engineering. First of all these are mass concrete dams which may include gravity and mass head buttress dams. They are widely used in modern hydraulic construction. One of the essential effects on such structures is temperature effect causing a change in stress-strain state of the structure both in construction and in operation periods. The temperature regime of the dam concrete massif during its construction is formed under effect of many factors. Prominence is given to external temperature effects: air temperature, foundation bed temperature, insolation effect, availability of wind and its direction. The main operating factor during construction is cement exothermic. The value of exothermic heating is affected by concrete mix composition: cement consumption and its heat release. Besides, the temperature field formation is affected by many technological factors: the concreting flow sheet, temperature of concrete placing, thickness of placed concrete lifts, concreting rate, use of artificial cooling of the concrete massif, etc. During the massif construction and cement intensive heat release a considerable heating of the massif zone occurs. This may result in great temperature differences which cause considerable tensile stresses and result in cracking [1, 2, 3, 4]. According to construction practice of mass concrete dams depending on «pinching» conditions and block location in the dam body (fig.1) the emergence of temperature cracks is connected with temperature differences [5, 6]: for blocks in the «pinching» zone (fig. 1, b), located near the foundation bed (the zone of the height roughly equal to the block length l bl), the main reason for cracking is the difference between the averaged temperature in the block in the exothermic period and the averaged temperature in the block during the operation period ΔТ 2 (fig. 1, d); for blocks in the «free» zone (fig. 1, b) the decisive factors is the difference between the temperature in the block center and on its external surface ΔТ 1 (fig. 1, g).
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Papers by Trong-Chuc Nguyen