Development of Drainage Soil Alternative Planting Material from Tamarind Fibers for Roof Garden

Abstract

The objectives of this article are to present the concept of developing drainable planting materials made from natural fibers for roof gardens. In this case, prototype tamarind fibers are developed as planting materials which promote plant growth similar to soil combined with the ability to effectively drain water around the roof garden. Under the concept of utilizing agricultural wastes to develop further innovations for growing plants on buildings by comparing the mechanical properties, suitability or limitation of various types of natural fibers that are popular and suitable for application as soil alternatives, this article presents forming of soil filter material for roof gardens made from end-process non-useable tamarind fiber. It demonstrates physical properties and basic properties of tamarind fibers for sheet forming without other binding materials and used as sample for analysis and estimation of stability period of the material, and fiber degradation period. The biodegradation tests were conducted using UV Weathering Test machine. The fibers were then tested for tensile strength and flexibility with 5-ton Tensile Testing Starrett machine in order to compare properties with general tamarind fibers.

The preliminary test results showed that tamarind fibers, which had been tested for 30, 90 and 180 cycles with UV Weathering Test (in this case, 1 Cycle is equal to 1 day under normal outdoor weather conditions) were able to withstand tensile strength up to 186.402 N/mm², 151.286 N/mm² and 133.230 N/mm² respectively. General tamarind fibers can withstand tensile strength of 273.242 N/mm² due to physical characteristics of the tamarind fibers which are tenacious and have high cohesive strength. When the planting materials are used in conjunction with other elements for roof garden system, the materials will be able to drain water on the roof garden because, when being soaked, tamarind fibers can inflate and expand creating porosities to allow water, air and nutrients to penetrate. At the same time, tamarind fibers also act as filter layer for other particles mixed with water, thus helping to drain water efficiently and prevent flooding. This feature would enable plants to grow well throughout their lifetime. The above mentioned test results can be used as guidelines to design and develop soil-alternative planting materials on roof gardens or applied to develop similar innovations. In addition, tamarind fibers are natural fibers derived from plants that have the potential to be developed for commercial purposes in the future.