Improvement of Sound Insulation Performance of ALC Walls Using Mock-up Experiments

Transcription

1 DOI /s y Iproveent of Sound Insulation Perforance of ALC Walls Using Mock-up Experients Chan H. Haan, and Seong S. Hong Received 10 Jun 2015 Accepted 23 Jul 2015 ipact noise. Also, The increasing deand of variable structure need light-weight aterials which can replace current dry walls and hardboards. Abstract Multi-unit dwelling has coprised the largest part of living in odern society where noise probles have becoe a social issue. Autoclaved lightweight concrete (ALC) panel and blocks have been widely used in residential, coercial and industrial buildings as its lightness and workability. However, the sound insulation perforance of ALC is not high due to its light weight and the porousness. This study aied to iprove the sound insulation perforance of ALC walls between housing units by changing the structure of the walls including layer of aterial, thickness of the air cavity, and connecting aterials. In order to this, coputer odeling and laboratory ock-up tests were undertaken to easure the STC of four different structures. As a result, the singlenuber quantities (Rw+C) of db, the first grade of sound insulation perforance, can be acquired when ALC blocks were constructed with gypsu board and air cavity connected with etal or resilient channel. ALC (Autoclaved Lightweight Concrete) block is a type of concrete produced by putting ceent and foaing agent into lie to ake a highly porous ixture and stea drying it at high teperature and high pressure. The advantage of ALC blocks is cheap and easy to use on construction site with good fire resistance and theral insulation perforance.[1] However, ALC block is vulnerable to sound insulation as it is light and consist of any air cavities. [2] In the present study, research has been undertaken in order to develop the coposite partition wall structure between housing units using ALC blocks satisfying 1st grade of sound insulation perforance. Keywords-coponent; autoclaved lightweight concrete block; sound insulation perforance; 1/1 scale ock-up experient; coputer odeling I. II. METHODS A. Sound Insulation Perforance Criteria INTRODUCTION Table 1 shows the standards of sound insulation perforance in three countries. Meanwhile Korea uses weighted sound attenuation coefficient (Rw+C), Japan uses D-curve and USA adopts STC curve. However, the results are quite siilar except the adjustent of sound insulation perforance in soe frequencies. Rapid industrialization and high degree of econoic growth have progressed speedily around urban areas since 1960s. Buildings of today are gradually becoing higher, larger and denser, and residential buildings are also following such a trend as seen in large apartents and high-rise residential/coercial coplex buildings. Such industrialization and econoic growth have brought about diverse probles such as various types of environental pollution, traffic noise and disasters, while the standard of living deanded by odern people is getting higher as a result of iproveent in the quality of life. Rw is a single nuerical evaluation aount of sound attenuation coefficient (sound transission loss). It was evaluated based on the KS F2862 as easured in the laboratory based on KS F2808.[3,4] C is a spectral adjustent ter that is defined in KS F2862, and applied to evaluate the sound insulation perforance decreases at a specific frequency band. The noise is the ost serious probles in odern ulti-dwelling buildings. The issue of the noise between chabers and dwelling units in apartents has becoe one of the biggest social probles in Korea at present which has to be resolved along with the issue of floor DOI: / _

2 TABLE I. At first, sound insulation perforances of 9 walls were calculated using Insul progra. The various input data were used for the calculation such as density, young odulus, thickness of each aterial, panel size, cavity absorption, stud spacing, frae type, air gap size, and roo volue. THE STANDARDS OF SOUND INSULATION PERFORMANCE IN THREE COUNTRIES Country / Standard Criteria Evaluation Frequency Range Korea / KS 2862 Rw-curve Weighted sound attenuation coefficient Hz 1/3 Octaveband Japan / JIS A USA / ASTM E 413 D-curve Daping value STC curve Sound Transission Class Hz Hz 1/1 Octave1/3 Octave-band band Interval of Revision of Adjustent of Rearks standard curve sound absorption spectru : C is 5 in receiving roo The su of deficiencies of TL at 16 frequencies do not exceed 32dB The axiu deficiency at any point should not exceed 8dB Rw or STC is the TL value at 500Hz on the STC contour In Korea, the criteria for the sound insulation perforance of the partition walls between each housing unit of apartents are defined in the 'Regulation related to the Criteria for House Construction' (Article 14)[5,6]. Also, the criteria for certification and anageent of the sound insulation structure of wall have been announced as in Table 2. Figure 1. The ethods and process of the study. As a next step, 1/1 real scaled ock-up experients of the sound insulation perforance of 9 walls were carried out in accordance with KS F 2808 Method of easuring the Airborne Sound Insulation Perforance of a Building Meber in a Laboratory.[3] Also, evaluations were undertaken in accordance with KS F 2862 Method of evaluating the Airborne Sound Insulation Perforance of a Building and a Building Meber.[4] All the experients were accoplished in the acoustic test roo of Korea Confority Laboratories in Korea.[7] The roo diension and floor plan of each reverberation chaber are listed in Table 3 and Fig.1. Fig.2 illustrates the of the installation process of the test walls equipped in the laboratories. 1) Reinforced concrete structure or steel-fraed structure ust be 15 c thick or thicker; 2) Plain concrete structure, concrete block structure, brick structure or stone structure ust be 20 c thick or thicker; 3) Concrete plate used as a eber of prefabricated house ust be 12 c thick or thicker; 4) The structure which the director of the Korea Institute of Construction Technology has designated certifying its sound insulation perforance in accordance with the criteria established and announced by the Minister of Land, Infrastructure and Transport (no ).[5] TABLE II. TABLE III. TEST ROOM PERFORMANCE CRITERIA OF SOUND INSULATION STRUCTURE Grade Grade criteria 58 Rw + C 2nd Grade 53 Rw + C 58 3rd Grade 48 Rw + C 53 ROOM MEASURE OF THE REVERBERATION CHAMBER B. Research Methods In the present study, in order to investigate the sound insulation perforance of walls, two ethods were used including coputer siulations and ock-up experients. Through the literature review, 9 types of partition walls were designed which consist of the cobination of ALC blocks and other aterials. Fig.1 illustrates the process of the study undertaken. Reverberation Chaber Volue( ) Roo Area( ) Floor Area( ) Source Roo Receiving Roo Figure 2. Plan of sound insulation test laboratory. 2

3 TABLE V. DETAIL SECTIONS OF 9 TEST WALLS Section of wall type 1 Figure 3. Set-up procedure of the test walls. C. Test Wall Specients Investigated All 9 test walls were built with the size of 3,600 2,750 and the thickness of all walls is 200 which is the liit of the partition wall size. the thickness of the ALC block was between 80 and 120, to which sound absorbing aterial, gypsu board and plastering were applied in addition.[8] The detailed setup of the wall and sectional view are as shown in Table 4 & 5. Table 4 lists the thickness of ALC blocks, gypsu board, air cavity and the stud types used. Also, Table 5 illustrates the section of 9 test walls with the order of aterial layers in detail. Section of wall type 2 All the test walls have air cavity filled with sound absorption aterials. Only two test walls (Type 4 & 5) have no gypsu boards and Type 3,4,5 has two layers of ALC blocks while other test walls have one layer of ALC blocks at center. Section of wall type 3 TABLE IV. DETAIL MATERIAL LAYERS OF 9 TEST WALLS Coposition Type Type 1 Type 2 Type 3 Type 4 Type 5 ALC Block s Gypsu Board Air Cavity Stud (10 Stud) 86 C-Stud + resilient channel = = =15 0 high strength GB high strength GB Type Type Type Type C-stud resilient channel 10 2 Section of wall type 4 PDS sheet furring channel 25 2 Section of wall type 5 defored Furring channel 25 2 resilient channel square-stud *total thickness is identical 20 3

4 fored as each drop in the sound insulation is inor. This sees to be because the resonant sound generated in the hollow layer is reduced by controlling it using the sound absorbing aterial, and no area in which the transission loss rapidly increases as the frequency increases has appeared. Section of wall type 6 Section of wall type 7 Figure 4. Measured sound insulation perforance of 9 test walls. Section of wall type 8 Aong 9 walls, it was found that Type 2 has highest sound insulation perforance which has the sallest ALC blocks however, it has two layers of gypsu board and air cavity on both sides. Type 2 has also highest sound insulation perforance in the low frequency band showing a rapid gradient. As the frequency oves fro the interediate frequency band where the ass law is valid to the low frequency band, the transission loss decreases due to coincidence effect in the bands of 400, 500 Hz and 800 Hz, after which, the closer the frequency oves to the high frequency band, the gentler the fored gradient is. The thickness of the air layer is secured by the hollow double wall, and the aterials that buffer and propagate acoustic waves at the low frequency band all using a sound absorbing aterial is presued to have played the role of vibration isolation. It was also revealed that test wall types 1,2 and 9 has the single-nuber quantities (Rw+C) satisfying the first grade with a value of 61dB, 68dB and 63dB respectively. Section of wall type 9 III. Test wall type 3 has a drop in sound insulation perforance at 125Hz, the gradient value rapidly increases in the interediate frequency band fro the 500 Hz band to 1,000 Hz band after gradual increase. The sound insulation perforance is the lowest in the low frequency band eanwhile the sound insulation perforance is shown to be the highest in the high frequency band. It sees that the sound insulation perforance of the high frequency band is secured by using a sound absorbing aterial. Also the transission loss is presued to have dropped in the low frequency band as a resonance phenoenon has occurred in the hollow layer inside the wall. The single nuber quantities satisfied third grade with a value of 48 db. RESULTS The result of easuring the sound insulation perforance of the 9 test walls are displayed in Fig.3 plotted in the function of frequency fro 100Hz to 3150Hz. In ost cases except type 3,4,5 though a slight dip effect is generated in the bands of 800Hz due to coincidence effect, a relatively gentle distribution curve is 4

5 Test wall types 4 & 5 has ost horizontal curves in the function of frequency. They have the gradient repeats increase and decrease in the low frequency band until 630 Hz, and shows a gentler gradient as the frequency gradually oves to the high frequency band. The low frequency band appears to be siilar to the transission loss area of a single wall, and it is presued that the resonance transission frequency has oved to the high frequency band as the thickness of the air layer in each hollow layer is reduced because of 3-ply wall structure. The sound insulation perforances of the type 4 & 5 are shown to be the lowest in the high frequency band as no sound absorbing aterial is used for high frequency. The single-nuber quantities (Rw+c) was shown to be 54 db, 51dB respectively. 1) It is iportant to build a hollow double wall with diverse wall aterials for better sound insulation 2) The use of air cavity filling with sound absorbing aterial is efficient for iprove sound insulation perforance especially preventing resonance transission phenoenon at low frequencies and coincidence effect at high frequency bands. 3) In order to prevent the drop of sound insulation perforance near the coincidence frequency, it is good to cobine different aterials or utilize elastic aterial. 4) Sound insulation perforance could be further iproved if the surface density of ALC block and sound insulation aterials is increased. Table 6 shows the both calculated and easured sound insulation perforance with the grades. As a result, aong 9 walls tested, 3 walls got 1st grade sound insulation perforance, two for 2nd grade and three for 3rd grade. TABLE VI. It can be expected that the result of the present study can be utilized for the iproveent of the sound insulation perforance of ALC block walls as well as siilar asonry structures. SOUND INSULATION PERFORMANCE OF 9 TEST WALLS ACKNOWLEDGMENT WITH GRADE Type Insul Calculated Rw+C Measure (db) Grade Type Type Type rd Grade Type nd Grade Type Grade Type Out of Grade Type rd Grade Type nd Grade Type IV. This work (Grants No.C ) was supported by Business for cooperative R&D between Industry, and Research Institute funded Korea Sall and Mediu Business Adinistration in REFERENCES rd [1] J.H.Suh, "A Study on the Effective Application Methods of ALC Block wall", Master's Thesis of Konkuk University [2] J.C.Na, "Developent of an Inter-Household Light Weight Wall for Iproveent of the Sound Reduction in the Apartents", Master's Thesis of Hanyang University, 2007 [3] Korean Agency for Technology And Standards, Method of easuring the Airborne Sound Insulation Perforance of a Building Meber in a Laboratory. KS F 2808, [4] Korean Agency for Technology And Standards, "Rating of airborne sound insulation in buildings and of building eleents", KS F 2862: [5] Ministry of Land, Infrastructure and Transport, "Isolation Structure Recognition of Walls and Manageent Standards( ), 2008 [6] Ministry of Land, Infrastructure and Transport, "Isolation Structure Recognition of Walls and Manageent Standards( ), 2014 [7] Research Institute of Industrial Science & Technology, Developent of light gauge steel-fraed walls with highly efficient sound insulation Noise and vibration reduction technology", Ministry of Environent, 2008 [8] C.H.Haan, "Experients on the Sound Insulation of Windows depend on the Material Changes of Window Gap and the Interior Reinforceent of Window Fraes", Proc. of the Architectural Institute of Korea, Vol. 8-1, DISCUSSION AND CONCLUSIONS This paper investigates the sound insulation perforance of various partition walls containing ALC blocks by the coputer prediction and ock-up experients. In general, it was shown that the sound insulation perforance of the structures proposed in this study were found to be superior to that of the existing ALC block walls as 3 test walls were first grade, 2 second grade and 3 test walls were third grade. Aong three types 1, 2, 9 which have 1st grade sound insulation perforance, it is recoended to use Type 9 due to the econoic feasibilities. The conclusions drawn fro the present study are as follows; 5

6 AUTHORS PROFILE Dr. Chan-Hoon Haan has been the Professor of Departent of Architectural Eng in Chungbuk National University, Korea, since He obtained the Bachelor of.eng fro Hongik University, Korea, in 1983, Master of Eng. for Yonsei University, Korea, in 1985, and Ph.D in Architectural Acoustics fro Sydney University., Australia, in He was the President of the Acoustical Society of Korea, fro 2013 to His research interests lie in Roo Acoustics, Acoustic Design of Auditoria, Noise Control in Building, and Floor Ipact Noise, Seong S. Hong obtained the Bachelor of.eng. fro Chungbuk University, Korea, in 2012, and Master of.eng. fro Chungbuk University, Korea, in His ajor fields are Architectural Acoustics, and Noise Control in Building This article is distributed under the ters of the Creative Coons Attribution License which perits any use, distribution, and reproduction in any ediu, provided the original author(s) and the source are credited. 6