PSI - Issue 71

Dharmadas Bairagi et al. / Procedia Structural Integrity 71 (2025) 417–423

421

Strength at 3 days (kN)

Strength at 3 days (kN)

3.00 3.10 3.20 3.30 3.40 3.50 3.60 3.70 3.80 3.90 4.00

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5

N/mm²

N/mm²

Lime binder

L20S80 L50S50 L80S20

B10 B16 B22 B28 B34 B40

3-days compressive strength of lime soil cube

4-days compressive strength of Lime Soil Bamboo filler cube

3.2. Selection of Optimum composition In present study dry density, thermal conductivity and MOR values of panels have been considered crucial parameter for selecting optimum proportion of bamboo fines amongst designed compositions. As per SP41: 1984, thermal conductivity of different bio-based insulation panels ranges from 0.04 to 0.1 W/mK. According to IS 3087 (2005) density of medium density particle board is from 0.4 g/cc to 0.9 g/cc. According to the GA-239(2019) publication on properties of gypsum board the minimum MOR for 9.5, 12.5 and 15.9mm thick board is 2.4,1.8 and 1.5 Mpa. The MOR is reducing with the increase in thickness. In the visual observation of panels casted with bamboo fines with 22% to 38% as total weight of dry binder mix at 4% interval, it was observed that panel with 30% and more bamboo fines has poor handling strength and easily breaks while handling. Wherein panel with less than 30% bamboo fines has dry density more than 0.9 g/cc (table 2) which does not comply to IS code requirement. Table 2: Dry density of Binder-bamboo fines (BB) panel Bamboo % 18% 22% 26% 30% 34% 38% Dry density(g/cc) 1.096 0.936 0.905 0.796 0.776 0.756 Thus to achieve a lower density with sufficient flexural strength, reinforcement was introduced and panels for BBC and BBM composition were tested for physical and mechanical properties. 3.3. Properties of panel Figure 5 indicates MOR values for all three compositions, It is observed that the panels with coir fiber have lowest MOR and the panels with coir fiber and paper treatment on surface has highest MOR amongst tested samples. Coir fibers are distributed evenly in matrix thus improve flexural cracking behaviour of panel. However, as the bamboo fines increase, total amount of fiber increases and thus coating of matrix is not sufficient resulting in reduction in MOR value. BBM panels also exhibit improvement in MOR up to 28% and there after it reduces. Several issues were found for the samples with continuous mesh reinforcement. Mesh was sandwiched by two layers of matrix and proper bond was not achieved thus desired MOR was not achieved. BBC compositions with surface treatment with paper exhibit improvement in MOR value. Maximum MOR is observed for 26% bamboo fines panel. Thus the panel with surface treatment attains the desired MOR value. Similar trends in observations were recorded for breaking strength test results as well (fig 6).