Thermal performance of a hollow core concrete floor system for passive cooling

1988 ◽  
Vol 23 (3) ◽  
pp. 243-252 ◽  
Author(s):  
Radu Zmeureanu ◽  
Paul Fazio
2019 ◽  
Vol 71 (10) ◽  
pp. 519-532 ◽  
Author(s):  
Fangzhou Liu ◽  
Jean-Marc Battini ◽  
Costin Pacoste

2016 ◽  
Vol 846 ◽  
pp. 12-17
Author(s):  
Ahmed Faheem ◽  
Gianluca Ranzi ◽  
Francesco Fiorito ◽  
Cheng Wang Lei

This paper presents a numerical procedure for modelling the thermal performance of ventilated hollow core slabs (VHCS). A turbulence model suitable for this purpose is identified first by considering a smooth horizontal pipe subjected to turbulent mixed convention conditions typical of VHCSs. Comparison of the fully-developed dimensionless velocity (u+) and temperature (T+) profiles as well as the Nusselt numbers (Nu) predicted by five different turbulence models against empirical expressions available in the literature shows that the Standard and Realisable k-ε models provide the best overall predictions of u+, T+ and Nu. Since the Standard k-ε model gives slightly better estimates of the Nu values, it is adopted to model the thermal performance of a VHCS geometry for which experimental thermal responses are reported in the literature. The numerical predictions of local temperatures within the VHCS agree well with the experimental measurements, and hence the Standard k-ε model is recommended here for the modeling of VHCSs.


2020 ◽  
Vol 23 (11) ◽  
pp. 2276-2291
Author(s):  
Rui Pang ◽  
Yibo Zhang ◽  
Longji Dang ◽  
Lanbo Zhang ◽  
Shuting Liang

This article proposes a new type of discrete connected precast reinforced concrete diaphragm floor system that consists of precast flat slabs and slab joint connectors. An experimental investigation of discrete connected new-type precast reinforced concrete diaphragm under a vertical distributed static load was conducted, and the effect of slab joint connectors on the load-bearing capacity was evaluated. Then, a finite element analysis of discrete connected new-type precast reinforced concrete diaphragm, precast reinforced concrete floors without slab connectors, and cast-in-situ reinforced concrete floor were performed to understand their working mechanism and determine the differences in load-bearing behavior. The results indicate that the load-bearing capacity and stiffness of discrete connected new-type precast reinforced concrete diaphragm increase considerably as the hairpin and cover plate hybrid slab joint connectors can efficiently connect adjacent precast slabs and enable them to work together under a vertical load by transmitting the shear and moment forces in the orthogonal slab laying direction. The deflection of discrete connected new-type precast reinforced concrete diaphragm in orthogonal slab laying direction is mainly caused by the opening deformation of the slab joint and the rotational deformation of the precast slabs. This flexural deformation feature can provide reference for establishing the bending stiffness analytical model of discrete connected new-type precast reinforced concrete diaphragm in orthogonal slab laying direction, which is vitally important for foundation of the vertical bearing capacity and deformation calculation method. The deflection and crack distribution patterns infer that the discrete connected new-type precast reinforced concrete diaphragm processes the deformation characteristic of two-way slab floor, which can provide a basis for the theoretical analysis of discrete connected new-type precast reinforced concrete diaphragm.


Designs ◽  
2020 ◽  
Vol 4 (3) ◽  
pp. 34
Author(s):  
Pedro F. Gois ◽  
Ângelo J. Costa e Silva ◽  
João M. P. Q. Delgado ◽  
António C. Azevedo ◽  
Ana S. Guimarães ◽  
...  

This work presents an extensive numerical simulation to analyze the influence of the coating layers on the performance of construction systems, in order to make the constructions projects feasible, not only economically but also technically. Through numerical simulations based on a defined reference model, the present work studied the influence of different layers of floor, roof and internal and external wall systems, on the acoustic, thermal, and luminous performance of buildings in Brazil. The results showed the materials and elements with the greatest influence on: lighting performance are the internal finishes of the environment and the type of glass used in the external windows. On thermal performance, all elements of the roofing system and façades, especially an absence of external cladding and the use of thermal blankets on the roof, have greater influence. The acoustic performance of the façade function on the external windows and acoustic performance of the floor system are mainly influenced by the thickness of the structural element and the use of a ceiling and acoustic blanket; acoustic performance of internal walls is affected by typology of the structured element of the wall and thickness.


2019 ◽  
Vol 149 ◽  
pp. 1154-1169 ◽  
Author(s):  
J. Uriarte-Flores ◽  
J. Xamán ◽  
Y. Chávez ◽  
I. Hernández-López ◽  
Nelson O. Moraga ◽  
...  

2020 ◽  
Vol 1006 ◽  
pp. 87-92
Author(s):  
Andrii Kovalov ◽  
Yurii Otrosh ◽  
Oleg Semkiv ◽  
Volodymyr Konoval ◽  
Oleksandr Chernenko

In the paper, the tests have been analysed for fire-resistant quality of the hollow-core reinforced-concrete floors with fire-retardant plaster covering under standard temperature regime of the fire. Using the methodology for determining the characteristics of fire-retardant coatings ability for reinforced-concrete floors, the dependences have been obtained of the fire-retardant coating thickness from the concrete protective layer of a hollow-core reinforced-concrete floor for a fire resistance limit of 180 minutes with a temperature regime of hydrocarbon fire and a tunnel curve according to the Netherlands standards (RWS). It has been concluded about the minimum required thickness of the studied fire-retardant coating to provide the required fire resistance limit of a hollow-core reinforced-concrete floor under the indicated fire regimes.


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