Erni Setyowati

Structural, acoustic, and aesthetic performances of double layer wall made of oyster shell and polymer as green material in green construction

The aim of research was to introduce green material for construction project by using waste material made of oyster shell and polymer as a substitute material to reduce the use of cement. In this research, the use of cement was replaced by oyster shell powder and mortar that was injected with polyurethane to lighten the weight on the structure. The methods used to find out the structure performance was DOE method based on the standards of ASTM 109/C 109M - 08 as well as the modulus of elasticity test. Acoustic test was also conducted with the standard test based on ASTM E 2611-09 and ASTM E 413. The aesthetic approach was conducted by an establishment of a model that represented the concept of double layer in the wall of the building. The results of this study proved that poly-urethane injection on mortar could decrease the weight of mortar by 20%. The absorption coefficient of polymer concrete was 0.9 – 1.00 at the frequency of 1500 – 2500 Hz and the Sound Transmission Loss (STL) of material was above 51 dB. Innovation of double layer building materials can be enriched by additional materials, such as natural fiber composite and fiber reinforced polymer. Aesthetically, the double layer wall material made of shells and polymer have a positive prospect to be used as construction material and can be applied in the architectural sphere as an aesthetic component of building, such as wall panel, wall ornament, double skin facade, and acoustical wall treatment.The aim of research was to introduce green material for construction project by using waste material made of oyster shell and polymer as a substitute material to reduce the use of cement. In this research, the use of cement was replaced by oyster shell powder and mortar that was injected with polyurethane to lighten the weight on the structure. The methods used to find out the structure performance was DOE method based on the standards of ASTM 109/C 109M - 08 as well as the modulus of elasticity test. Acoustic test was also conducted with the standard test based on ASTM E 2611-09 and ASTM E 413. The aesthetic approach was conducted by an establishment of a model that represented the concept of double layer in the wall of the building. The results of this study proved that poly-urethane injection on mortar could decrease the weight of mortar by 20%. The absorption coefficient of polymer concrete was 0.9 – 1.00 at the frequency of 1500 – 2500 Hz and the Sound Transmission Loss (STL) of material was above 51...

On the Sound Absorption Improvement of Water Hyacinth and Coconut Husk based Fiber Reinforced Polymer Panel

This paper emphasizes on the sound absorption improvement of the water hyacinth and coconut husk based fiber reinforced polymer (FRP) panel. The dry water hyacinth and coconut husk were milled and sieved before it mixed with polyester and methyl ethyl ketone peroxide as the catalyst. The composition is 200 ml, 25 grams, and 20 ml for the polyester, fiber, and catalyst respectively. The mixture casting is by using a square tray to form a flat FRP panel through open air drying without any compaction process. Three different approaches i.e. multiple quarter wavelength resonators, air cavity, and front fibrous layer inclusion are implemented to the FRP to improve its sound absorption performance. The entire measurements conducted by using transfer function based impedance tube technique refer to ASTM E-1050-98 standard. B&K 4206. It found that the proposed approaches are increase sound absorption coefficient of the bulk FRP significantly. The best performance occurred on the coconut husk based FRP when the 8 of quarter wavelength resonators combined with the fibrous layer. Sound absorption increased accordingly to above of 0.7 starting from 1.5 kHz. On the other side, the air cavity shows similar influence on the entire test sample due to Helmholtz resonance mechanism.

Thermal condition in Semarang Cathedral’s passive cooling system

Nowadays, passive cooling system is no longer the top priority among the design concept for public buildings in Indonesia. However, the passive cooling system once became an effective building technology to cope with tropical climate in the Dutch colonial era. Semarang City, Central Java, has an outstanding heritage building equipped with passive cooling system, named Semarang Cathedral Church. This church was also built in the Dutch East Indies era and inaugurated in 1940. Research was held in 5 (five) times of church service and 9 (nine) measuring points where low ventilation was opened and closed during church service. Dry bulb temperature, effective temperature, relative humidity, and air velocity, were measured. The purpose of this study was to examine the thermal condition of the building with only passive cooling system. Thermal measurement and site observation were carried out. The results of this study show that there is a significant change on thermal condition inside building as the effect of l...

The comparison of vernacular residences’ thermal comfort in coastal with that in mountainous regions of tropical areas

Adaptive thermal comfort is the latest theory used to analyze thermal acceptability of the naturally ventilated buildings for occupants in tropical areas. Vernacular residences are considered capable to meet the thermal comfort for the occupants. The combination between adaptive and passive theory is still rarely conducted. This study aims to compare the adaptive and passive thermal comfort for occupants of vernacular residences in mountainous and coastal regions using AMV (Actual Mean Vote) and PMV (Predicted Mean Vote). This research uses a quantitative method with a statistical analysis on variables of air temperature, globe temperature, velocity, relative humidity, age, weight, and height. AMV data are collected based on questionnaires with ASHRAE (American Society of Heating, Refrigeration, Air conditioning Engineering) standards. The samples consist of 100 vernacular residences of both coastal and mountainous regions. The results show that there are AMV and PMV differences in each region. The AMV values in those vernacular residences in mountainous and coastal regions are respectively -0.4982 and 0.1673. It indicates that the occupants of vernacular residences in coastal regions accept the thermal conditions better. Thus, it can be concluded that vernacular residences in coastal areas comfort the occupants more.Adaptive thermal comfort is the latest theory used to analyze thermal acceptability of the naturally ventilated buildings for occupants in tropical areas. Vernacular residences are considered capable to meet the thermal comfort for the occupants. The combination between adaptive and passive theory is still rarely conducted. This study aims to compare the adaptive and passive thermal comfort for occupants of vernacular residences in mountainous and coastal regions using AMV (Actual Mean Vote) and PMV (Predicted Mean Vote). This research uses a quantitative method with a statistical analysis on variables of air temperature, globe temperature, velocity, relative humidity, age, weight, and height. AMV data are collected based on questionnaires with ASHRAE (American Society of Heating, Refrigeration, Air conditioning Engineering) standards. The samples consist of 100 vernacular residences of both coastal and mountainous regions. The results show that there are AMV and PMV differences in each region. The AMV va...

Building Materials Composition Influence to Sound Transmission Loss (STL) Reduction

The development of the airport always causes the noise impact to the surrounding environment.1 Housing close to the airport will be annoyed by the aircraft noise, especially if the building is not added by absorber building materials. Housing lay out towards the runways as noise sources is also an aspect that should be considered. This research resulted building models equipped by simple material compositions that had capability in reducing the airport noise optimally. The decrease of the noise level found out from the research is caused by the value of Sound Transmission Loss (STL) of the building materials composition. The models of housing are laid out with a number of specific orientation angles towards the runway and resulted values of the highest noise level reduction.