Field impact noise test data on a concrete floor structure

1996 ◽  
Vol 100 (4) ◽  
pp. 2770-2770
Author(s):  
Roy L. Richards ◽  
Ioana Park
Keyword(s):  
Test Data ◽  
Concrete Floor ◽  
Impact Noise ◽  
Floor Structure ◽  
Noise Test

scholarly journals CRACK FORMATION IN VACUUM CONCRETE

2002 ◽  
Vol 8 (2) ◽  
pp. 117-120
Author(s):  
Grigory Yakovlev ◽  
Nikolai Khokhriakov
Keyword(s):  
Crack Formation ◽  
Concrete Strength ◽  
Horizontal Displacement ◽  
Concrete Surface ◽  
Concrete Floor ◽  
X Ray ◽  
Floor Structure ◽  
Concrete Coating ◽  
Concrete Solution ◽  
Skeleton Structure

The reasons of crack formation in vacuum concrete floors with reinforcing mineral wear-resistant coating were investigated. The main reasons of crack formation are connected with low concrete strength due to the lack of water for cement hydration, the absence of shrinkage seams in floor structure, wrong reinforcement and excess thickness of strengthening mineral coating of concrete floor which initiates the crack formation. At the concrete thickness 150 mm, the depth of crack spreading was 115 mm, the concrete strength in kerns—14.2–24.8 MPa instead of 30 MPa as planned, and the concrete macrostructure had the signs of lamination. Besides, an air clearance up to 4 mm in size was found between the foundation and concrete floor. The reinforcement skeleton structure in concrete floors did not envisage the possibility of horizontal displacement of concrete coating in the square limited by deformation seams, and the deformation seams did not penetrate into the depth planned eliminating their formation during concrete hardening. X-ray phase analysis of fresh hardening coating of concrete surface showed the presence of ettringite in it, and non- hydrated Portland cement minerals prevailed in the structure of concrete solution resulting in insufficient strength of the concrete hardened. Thus, due to the considerable heterogeneity of vacuum concrete structure and properties by thickness, the presence of the initiator of crack formation in the concrete upper layer (ettringite) and wrong reinforcing the formation of uneven shrinkage phenomena in hardening cement takes place resulting in crack net formation in the upper stretched concrete area.

Subjective Response to Foot-Fall Noise, Including Localization of the Source Position

2011 ◽  
Vol 97 (5) ◽  
pp. 904-908 ◽  
Author(s):  
Jonas Brunskog ◽  
Ha Dong Hwang ◽  
Cheol-Ho Jeong
Keyword(s):  
Subjective Response ◽  
Reverberation Time ◽  
Source Position ◽  
Impulse Responses ◽  
Surface Source ◽  
Lightweight Structures ◽  
Impact Noise ◽  
Vibration Field ◽  
Floor Structure ◽  
Current Standards

Although an impact noise level is objectively evaluated the same according to current standards, a lightweight floor structure is often subjectively judged more annoying than a heavy homogeneous structure. The hypothesis of the present investigation is that the subjective judgment of impact noise is more annoying if the source position can be localized; lightweight structures have a more localized radiation than heavy structures. For the heavy structures the reverberant vibration field is dominant, therefore having a distributed radiation. A listening test is used to assess the subjective annoyance, using simulated binaural room impulse responses, with sources being a moving point source or a non-moving surface source, and rooms being a room with a reverberation time of 0.5 s or an anechoic room. The paper concludes that no strong effect of the source localization on the annoyance can be found.

scholarly journals Thermal Performance Analysis of Reinforced Concrete Floor Structure with Radiant Floor Heating System in Apartment Housing

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Young-Sun Jeong ◽  
Hae-Kwon Jung
Keyword(s):  
Thermal Conductivity ◽  
Reinforced Concrete ◽  
Heat Loss ◽  
Heating System ◽  
Expanded Polystyrene ◽  
Radiant Heating ◽  
Concrete Floor ◽  
Floor Structure ◽  
Radiant Floor Heating ◽  
Floor Heating

The use of the resilient materials in the radiant floor heating systems of reinforced concrete floor in apartment housing is closely related to the reduction of the floor impact sound and the heating energy loss. This study examined the thermal conductivity of expanded polystyrene (EPS) foam used for the resilient material in South Korea and analysed the thermal transfer of reinforced concrete floor structure according to the thermal conductivity of the resilient materials. 82 EPS specimens were used to measure the thermal conductivity. The measured apparent density of EPS resilient materials ranged between 9.5 and 63.0 kg/m3, and the thermal conductivity ranged between 0.030 and 0.046 W/(m·K). As the density of resilient materials made of expanded polystyrene foam increases, the thermal conductivity tends to proportionately decrease. To set up reasonable thermal insulation requirements for radiant heating floor systems, the thermal properties of floor structure according to thermal insulation materials must be determined. Heat transfer simulations were performed to analyze the surface temperature, heat loss, and heat flow of floor structure with radiant heating system. As the thermal conductivity of EPS resilient material increased 1.6 times, the heat loss was of 3.4% increase.

Effect of Acoustic Pads' Different Dynamic Stiffness on the Reduction of Impact Sound Level

2014 ◽  
Vol 899 ◽  
pp. 491-494 ◽  
Author(s):  
Lenka Autratová ◽  
Petr Hlavsa
Keyword(s):  
Optimal Design ◽  
Transmission Loss ◽  
Dynamic Stiffness ◽  
Sound Level ◽  
Sound Insulation ◽  
Sound Transmission Loss ◽  
Acoustic Insulation ◽  
Impact Noise ◽  
Floor Structure ◽  
The Impact

Impact sound transmission loss is the ability of structure to absorb impact noise, which is formed by mechanical impulses (steps, falls). The impact noise is then spread to the elements connected to the floor structure, such as the ceiling and surrounding wall. Dynamic stiffness is one of the important parameters that affect the sound insulation of ceiling structures with floating floors. The article deals with the optimal design of acoustic insulation to the floor composition, combining different materials of various thicknesses with various characteristic properties.

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