PENGARUH KETEBALAN ADHESIF EPOKSI/SERBUK ALUMINIUM DAN SURFACE TREATMENT TERHADAP KEKUATAN GESER SINGLE LAP JOINT PLAT ALUMINIUM/CFRP

Penelitian ini bertujuan untuk menyelidiki pengaruh ketebalan adhesif epoksi/serbuk aluminium dan surface treatment terhadap kekuatan geser, serta mengamati karakteristik penampang patah single lap joint plat aluminium/CFRP. Identifikasi karakteristik penampang patah dapat menjelaskan kekuatan geser single lap joint plat aluminium/CFRP. Plat Al 2024, CFRP, resin bisphenolic, promotor P-EX, katalis MEKPO, adhesif epoksi, serbuk aluminium, dan larutan kimia merupakan bahan dalam penelitian ini. CFRP dibuat dengan proses hand lay-up dengan 30% (w/w) serat karbon dan 70% (w/w) resin bisphenolic. Kandungan adhesif terdiri dari epoksi A dan B (1:1), dengan penambahan filler serbuk aluminium (12,5% dari berat total adhesif). Formula adhesif dicampur menggunakan mixing machine selama 6 menit pada kecepatan 60 rpm. Adhesif epoksi/serbuk aluminum dilaminasi pada kedua adherend. Waktu mulai penekanan adalah 20 menit, kemudian area sambungan ditekan pada tekanan 9 bar selama 6 jam. Variasi yang digunakan adalah ketebalan adhesif epoksi/serbuk aluminium (0,2 mm ; 0,4 mm ; 0,6 mm ; 0,8 mm ; 1 mm) dan surface treatment (acetone, chromate sulphuric acid, caustic etch, tucker’s reagent) pada plat Al 2024. Sebelum pengujian geser, semua spesimen diberikan perlakuan post cure dengan suhu 1000C selama 15 menit. Hasil penelitian menunjukkan bahwa: (1) peningkatan ketebalan adhesif dari 0,2 mm ke 0,4 mm menyebabkan peningkatan kekuatan geser single lap joint plat Al 2024/CFRP. Namun ketebalan adhesif di atas 0,4 mm menyebabkan penurunan kekuatan geser secara signifikan. Perilaku ini disebabkan oleh sifat adhesif epoksi/serbuk alumunim yang brittle; (2) surface treatment, acetone, menghasilkan kekuatan geser terbaik dengan nilai 9,31 N/mm2. Acetone menyebabkan lamination (pembasahan) adhesif terhadap permukaan plat Al 2024 lebih merata; (3) jenis kegagalan sambungan, mixed failure (light-fiber-tear failure dan cohesive failure), mengindikasikan kekuatan geser tertinggi. Kata kunci : CFRP, ketebalan adhesif, surface treatment, kekuatan geser, jenis kegagala

Pengaruh Kandungan Dan Ukuran Serbuk Genteng Sokka Terhadap Ketahanan Bakar Komposit Geopolimer

The objective of this research is to investigate the effect of particle content and grain size of Sokka roof tile powder on the burning endurance of the composite of Sokka roof tile powder - ripoxy R-802.The materials used were a Sokka roof tile powder (SGS), ripoxy R-802 resin, MEKPO catalyst and P-EX promotor. The Sokka roof tile powder was generated from the rejected Sokka roof tile which was crushed into powder. The powder was sieved to result in three size variances, which were mesh 80 retained in mesh 100 (177μm-149μm), mesh 150 retained in mesh 200 (99μm-74μm), and breaking away from mesh 200 (≤74μm). Prior to getting mixed with the resin, SGS was heated in an oven for 45 minutes in the temperature of 105oC. Afterwards, the powder was mixed with ripoxy R-802 resin for 3 minutes. The variances of SGS content were determined to be 10%, 20%, 30% and 40% composition. Making composite was conducted by press mould. Fixed composites was given post curing treatment in the temperatures of 80oC for 120 minutes. The burning testing on the composite was conducted on the basis of the standard of ASTM D-635. The indicator of burning endurance was determined by the data of time of burning (TOB) and rate of burning (ROB). The TOB resulted from the time of ignition and the ROB resulted from the time of fire propagation time in the composite. The results of this research are as follows: (1) the addition of SGS can improve the burning endurance of the composite of SGS-ripoxy R-802 as indicated by the increase in the TOB but the decrease of ROB due to the addition of the content of SGS; (2) the small size of the particle of SGS can increase the burning endurance of the composite of SGS-ripoxy R-802 as signified by the increase in the TOB but the decrease in the ROB due to the small size of the particle of SGS which breaks away from mesh 200 (≤74μm)