This study aims to determine the use of corn cob ash as an additive to cement in the production of CLC lightweight bricks according to SNI 03-2156-1991 concerning air flow light brick blocks by autoclaving process. The method used is an experiment in accordance with SNI 03-2156-1991 regarding light brick blocks of air flow with autoclaving process. The test object measures 59 × 19 ×10 cm and uses 45 specimens. The results obtained for dimensional testing exceed the required limits of SNI 03-2156-1991. The compressive strength of lightweight bricks is obtained at variations of 0%, 4%, 6%, 8%, and 10% respectively 3.07 N/mm², 3.68 N/mm², 4.54 N/mm², 4.29 N/mm², and 4 N/mm² with the optimum compressive strength value obtained at 6% variation and non-passing variation at 0% variation with a minimum requirement of 3.6 N/mm². The flexural strength of lightweight bricks is obtained at variations of 0%, 4%, 6%, 8%, and 10% respectively 0.27 N/mm², 0.63 N/mm², 0.81 N/mm², 0.65 N/mm², and 0.76 N/mm with optimum flexural strength values obtained at 6% variation and non-qualifying variations at 0% and 4% variations with a minimum requirement of 0.65 N/mm².

The increasing production of shrimp commodities in Bangka Belitung Island can cause shrimp shell waste and polluting the environment. Shrimp shell waste can further proceed into chitosan which has a wide range of functions in various fields. This current study aims to find out the influence of the deacetylation process in chitosan extracts from shrimp shell waste. The method of chitosan extraction by varying repetition of deacetylation process. The characterization of chitosan extracts by FTIR analysis to determine functional group and degree of deacetylation (DD). Based on FTIR spectra, repetition in the deacetylation process in chitosan extraction still produces chitosan extracts that do not fully transform into chitosan. However, it able to increase DD with the highest DD of chitosan extract constitutes 86,78% and can be used in the further application.