Seismic performance of coconut-fibre-reinforced-concrete columns with different reinforcement configurations of coconut-fibre ropes

• Columns with three different rope configurations were considered.
• Coconut-fibre-reinforced-concrete and coconut-fibre ropes were used.
• Columns were tested under scaled El Centro earthquake loadings.
• A decrease in columns natural frequency was observed with incremental loading.
• Out of three, column with multiple central coconut-fibre ropes performed well.

Three different reinforcement patterns of coconut-fibre ropes in columns are investigated in this experimental study. Coconut-fibre-reinforced-concrete is used to cast columns. This new material is under investigation for the production of low cost but safe housing in earthquake prone regions. Overall ductile behaviour of structure is a basic requirement; therefore coconut fibres are selected because of their highest toughness amongst all natural fibres. Incremental ground motion excitations are applied to the columns using a shake table. The excitations are time-scaled to produce damage in columns. This is to match the frequency of excitation with that of structure. The dynamic properties of coconut fibre and rope reinforced concrete columns are determined by an impact test after each excitation. A change in natural frequency is observed, showing that there is some non-visible material degradation in the specimen before cracking. Out of three patterns, column with multiple central ropes performed well showing rocking phenomenon.