*3.3.3. The building physical comfort*

**3.3. The modern Balinese house**

78 Bamboo - Current and Future Prospects

*3.3.2. Structural performance of the house*

**Table 5.** The house characteristics.

system.

*3.3.1. The characteristics of the house used as the sample*

The characteristics of the modern house used as the sample in this present study included the whole area of the house, the area of the room, the area of the terrace, the height of the wall, the number, height and width of the door. All the componential dimensions were adjusted to the dweller's anthropometry as presented in **Tables 5** and **6** [24]. **Figure 12** [24] shows a modern Balinese house which built of concrete block wall with a bamboo‐reinforced concrete

The structural performance is defined as a ratio of the most maximum horizontal displace‐ ment to the height of the building. The building was analyzed in three‐dimensional model as

**Nbr. Description Width (cm) Height (cm) Reinforcement area** 

1 Sloof (concrete) 20 25 8.40 2 Column (concrete) 20 20 11.20 3 Beam (concrete) 18 30 7.00 + 2.80

4 Gording (wood) 6 12 – 5 Rafter 5 6 – 6 Lisplank (wood) 2 20 –

**Table 6.** The characteristics of the house structural component.

**(cm2 )**

**Nbr. The house characteristics Volume Unit** Area of the building 35 m2 Area of the room 2 × 12.5 m2 Area of the terrace 1 × 10.5 m2 Height of the wall 3.1 m' Number of the doors 2 pieces Number of the windows 2 pieces Foundation material Stone – Wall material Concrete block – The hood Hood – Roof material Pressed tile – Floor material Ceramic –

The measured building physical comfort included the temperature, humidity, noise, and the natural illumination. It was measured at 6 a.m., 12 a.m., 6 p.m., and 12 p.m. The results of the measurement are presented in **Table 7** [24].

**Figure 12.** The simple modern Balinese house with the bamboo reinforced concrete structure and concrete block wall [24].

**Figure 13.** Model and deformation of house structure [24].


load, and wind load), and bamboo reinforced concrete structure could be used to construct the simple modern Balinese house. It can be stated that the two types of the houses are safe enough for the dwellers. The bamboo reinforced concrete structure was already applied to constructing two storied houses. It was stated in the study conducted by Virgyan [26] that the multiple bam‐ boo reinforced portal concrete structure that was bridled at the construction location with plas‐ tic joints can be used in the construction of a simple house, which is resistant to the earthquake. Based on the result of the three‐dimensional analysis, it can be stated that the performance of the structural system is highly good, making the dwellers feel so safe. The performance of the structural system when planning to construct a building, which is resistant to the earthquake in Indonesia, is highly important as it is highly possible for the earthquake to take place in almost

Safe, Simple and Comfortable House with Bamboo Reinforced Concrete Structure

http://dx.doi.org/10.5772/intechopen.68543

81

The thermal comfort or the house physical environment is affected by the temperature, rela‐ tive humidity, speed of the wind, illumination, and noise. The temperature within the room in the traditional Bali age house ranges from 21 to 27°C, and the temperature within the room in the modern Balinese house ranges from 26 to 32°C. At certain hours, it is higher than what is required. In the equatorial region, the comfortable temperature ranges from 22.5 to 29.5°C

The relative humidity both within and outside the room is almost the same, namely 60% dur‐ ing daytime and 80% at night. It will be better if the relative humidity is higher than 20% all the year round, and lower than 60% during the summer and lower than 80% during the win‐ ter [11]. If the relative humidity is higher than 80%, there will be water vapor on the human skin, making the body uncomfortable [17, 19]. In addition, the dweller will not be in good

The speed of the wind within the room ranges from 0.1 to 0.4 m/second during daytime. At night, it is 0 m/second as the window and ventilation are closed. The speed of the wind can contribute to the speed of the missing heat due to convection and evaporation. Therefore, the speed of the wind ranging from 0.1 to 0.3 m/second can fulfill what is required for being comfortable [11, 13]. It should not be faster than 0.2 m/second [10]. As the speed of the wind is in accordance with what is required by the experts mentioned above, the weather within the room circulates well, causing the dweller's health to improve and the eyes to be less irri‐ tated. The front window and the ventilation at the rear wall affect the speed of the wind and cause the cross‐weather circulation to take place. This is supported by the result of the study conducted in Ref. [15], in which it is stated that the cross‐weather circulation can improve the comfort of those who stay at the simple houses located in Cemara Giri area, Dalung, Bali. The natural illumination within the room ranges from 145 to 255 Lux during daytime, higher than what is required, namely 115 Lux [27]. The intensity of the natural illumination within the room is affected by how wide the window is open and how wide the ventilation is. The win‐ dow or ventilation is installed at the front and rear walls, causing the fresh weather to circulate from the front window and the dirty weather to get out from the rear ventilation. The dweller becomes comfortable and the electric energy can be saved. The maximum use of the natural illumination does not only positively contribute to the dweller's health but also saves the electric

[12], from 21.37 to 28.37°C (ASHRAE), and from 22.8 to 30.2°C [21].

health and, for example, there will be fungus on the skin.

every part of Indonesia [28].

*3.4.3. Thermal comfort*

**Table 7.** The physical comfort of the modern Balinese house.

#### **3.4. Discussion**

#### *3.4.1. Construction material*

The construction forming materials tested in the laboratory included the compressive strength of the concrete block, the compressive strength of the brick, the compressive strength of the concrete, and the tensile strength of the bamboo. The materials were tested as the data used to analyze the performance of the house structure. The results showed that the compressive strength of the concrete block averaged 4.96 MPa and the compressive strength of the brick averaged 2.04 MPa. The compressive strength of the concrete cylinder with a diameter of 150 mm and a height of 300 mm averaged 21.12 MPa or equal to K‐260 kg/cm<sup>2</sup> , meaning that the standard SNI – 213 for concrete was already fulfilled which requires that the minimum strength of the concrete structure in an area which is sensitive to the earthquake such as Bali should be 20.75 MPa and equal to K‐250 kg/cm2 .

Bamboo test results show in **Table 1**, in which the tensile strength of the bamboo averaged 129.17 MPa and the rupture strength averaged 191 MPa, so the over strength was 47.86%. The melting and tensile strength *fy* = 129 MPa was used to design and analyze the diameter of the item tested. Bamboo can be used as the alternative reinforced concrete structure in the con‐ struction of a simple house. In addition, it is cheap and can be found anywhere in Bali. This is supported by the result of the study conducted in Ref. [5], stating that bamboo can be used as an alternative material of construction because it is cheap and saves energy. According to Ref. [9], the tensile strength of the bamboo ranges from 200 to 300 MPa, its flexibility averages 84 MPa and its elastic modulus is 200.000 MPa. Viewed from its tensile strength, it is feasible enough to use as the concrete reinforcement, at least for the light and medium structure. Furthermore, according to Ref. [14], bamboo can be used as the reinforcement of the concrete structure as its rupture strength is high enough [16].

#### *3.4.2. Safety and performance of construction*

Based on the compressive strength of the concrete and the tensile strength of the bamboo, it can be stated that the bamboo‐reinforced concrete structure with brick walls used to construct the traditional Bali age house is resistant enough to load assigned (dead load, live load, earthquake load, and wind load), and bamboo reinforced concrete structure could be used to construct the simple modern Balinese house. It can be stated that the two types of the houses are safe enough for the dwellers. The bamboo reinforced concrete structure was already applied to constructing two storied houses. It was stated in the study conducted by Virgyan [26] that the multiple bam‐ boo reinforced portal concrete structure that was bridled at the construction location with plas‐ tic joints can be used in the construction of a simple house, which is resistant to the earthquake. Based on the result of the three‐dimensional analysis, it can be stated that the performance of the structural system is highly good, making the dwellers feel so safe. The performance of the structural system when planning to construct a building, which is resistant to the earthquake in Indonesia, is highly important as it is highly possible for the earthquake to take place in almost every part of Indonesia [28].
