# Precast Bridges of Bamboo Reinforced Concrete in Disadvantaged Village Areas in Indonesia
## 1 Introduction  
The continued use of industrial products has caused permanent pollution. Permanent pollution is environmental pollution caused by industrial waste without recycling or the continuous use of raw materials from nature without renewal. The use of bamboo as a renewable building material can reduce pollution and maintain a healthy environment [1]. Bamboo is a grass plant with cavities and nodes in its stems [2]. Bamboo is a renewable building material, such as wood. Bamboo has the advantage of being economical, growing fast, and does not take long to achieve mechanical resistance. Mechanical resistance of bamboo, such as tensile strength, flexural strength, and other mechanical properties, can be achieved in a relatively fast time, namely at the age of bamboo ranging from 3-4 years [3]. Bamboo is also very abundant in tropical and subtropical areas around the world [1]. Indonesia is a country with a tropical climate. One of the plants that can thrive in Indonesia is bamboo. Bamboo is scattered throughout Indonesia. Bamboo has been widely used as a material for simple structures, such as warehouses, bridges, and village traditional houses, and for handicrafts for rural communities. In Indonesia, there are more than 100 species of bamboo. Around the world, there are \(\pm\)1500 species of bamboo [4]. In terms of its potential, in 2000 the total area of bamboo plants in Indonesia was 2,104,000 ha, consisting of 690,000 ha of bamboo planted in forest areas and 1,414,000 ha of bambooplant areas outside forest areas [5]. [PERSON] (2015) [5] revealed that in the Hulu Sungai Selatan Regency, the bamboo area was estimated to be around 22,158 ha, with a production of about 3000 stems/ha. The description of the potential for bamboo production in East Java is 29,950,000 stems/year, Yogyakarta 2,900,000 stems/year, Central Java 24,730,000 stems/year, and West Java 14,130,000 stems/year [6]. With such a large production potential, efforts must be made to increase its economic value, including being used as an alternative to concrete reinforcement. The best bamboos that are widely used as structural elements are the petung bamboo (_Dendrocalamus asper_) and ori bamboo (_Bambusa blumeana_), because these two bamboos have the best technical specifications with a high tensile strength. The use of bamboo as concrete reinforcement for simple construction is applied specifically in underdeveloped village areas that have a lot of bamboo. Bamboo for concrete reinforcement is because it has a relatively high tensile strength. The tensile strength of bamboo can reach 370 MPa in its outer fibers [1]. The failure of the elements of the bridge frame or roof truss usually occurs in the tensile stem elements. Bamboo has a high enough tensile strength suitable for use in tensile elements. Bamboo is suitable for use in tensile elements, simple construction, such as roof trusses, simple bridge trusses, simple house construction elements, and so on. [PERSON] et al. (2018) [7] tested the pull-out of bamboo reinforcement with a layer of Sikadur\({}^{\circledR}\)-752 and hose clamps embedded in a concrete cylinder, showing an increase in tensile stress of up to 240% compared to untreated bamboo reinforced concrete (BRC). A single BRC beam with a bamboo reinforcing area ratio of 4% exceeds the ultimate load of a steel-reinforced concrete (SRC) beam by 38.54% with a steel reinforcement area ratio of 0.89% [8]. However, bamboo also has weaknesses, which are being easily attacked by insects and having high water absorption. This study did not test for fungal and insect attacks, but the technology to prevent fungus and insect attack was based on the opinion and research of [PERSON] (1911) [2] and [PERSON] (1904) [9], namely that soaking in water for two months is sufficient to prevent insect attack. Soaking and drying aim to remove the starch or sugar content in bamboo. The criterion for sufficient soaking is that the bamboo smells bad.