A study on the use of bamboo as reinforcement to concrete mixed with seawater (2013)
-Alarming issues such as depletion of renewable freshwater and shortage in cement, especially in the Philippines, are evident nowadays. Traditionally, steel is used as reinforcement to concrete to compensate its low tensile strength. However, structural steel is only limited to some countries due to its limited natural resource and lack of skilled labor. Consequently, the use of suitable materials as alternative reinforcements to concrete, such as bamboo, are highly recommended due to its ease of availability, low cost, lightweight characteristics, flexibility and toughness. The significance of this study is directed towards sustainable development wherein alternative construction materials are being tested for their effectiveness in construction. However, the use of bamboo as reinforcement in concrete is very limited due to its various uncertainties. This study investigates the effectiveness of bamboo as reinforcement in concrete, replacing concrete’s water mixing component with seawater and substituting 20% of its cement constituent with fly ash. The parameters studied in this research are the compressive strength, tensile strength of bamboo, reinforcement’s pullout bond characteristics with concrete, and its behavior as reinforcement to concrete with respect to flexure. The compressive and pullout tests considered cylindrical specimens while beam specimens with rectangular cross-section were used to test the flexural strength. After 28 days of curing, the compressive strength of the concrete mixed with seawater (CMSW) samples attained a higher compressive strength than concrete mixed with freshwater (CMFW) samples because of the seawater and flyash which increase the development of compressive strength. Though the compressive strength of CMSW was greater than CMFW, the T-test suggests that there was no significant difference between the control sample and the substituted samples. Pullout results suggest that there was a significant difference in the steel embedded pullout specimens and bamboo pullout specimens. The corrugations of the steel proved to add bond with the concrete. Tensile test results show that the strength of steel in tension is significantly greater than the bamboo samples. Results also show that the as the number of nodes increased, the tensile strength of the bamboo decreased. The flexure strength of steel reinforced beams is significantly greater than bamboo reinforced beams. In addition, as the number of nodes increased, the resistance to flexure also increased.
Engr. Cheryl Lyne C. Roxas