Pengaruh Kondisi dan Temperatur pada Sifat Mekanis Tiga Jenis Bambu

Abstract

Sifat fisis dan mekanis bambu perlu diketahui jika bambu dimanfaatkan sebagai material konstruksi. Bambu untuk konstruksi eksterior cenderung berhubungan dengan kondisi lingkungan yang sering berubah dan perbedaan suhu harian siang dan malam yang cukup tinggi, sehingga faktor temperatur diperlukan untuk mempertimbangkan keamanan dan mengurangi resiko bahaya rubuh. Penelitian ini bertujuan membandingkan sifat fisis dan mekanis bambu yang menerima beberapa macam temperatur pada kondisi kering dan basah. Penelitian juga menghitung faktor temperatur (Ct) bambu secara empiris dalam kondisi kering dan basah serta membandingkan nilainya dengan SNI 7973:2013. Faktor temperatur (Ct) digunakan sebagai faktor koreksi tegangan ijin (allowable stress) pada analisis struktur konstruksi yang menerima suhu di atas suhu kamar. Nilai faktor temperatur (Ct) diperoleh sebagai rasio nilai sifat mekanis bambu kondisi basah dan kering yang menerima suhu tertentu (0 °C, 38 °C, 45 °C, dan 60 °C) dibandingkan sifat mekanis pada kondisi standarnya (kering bersuhu 38 C). Penelitian ini menggunakan tiga jenis bambu yaitu andong (Gigantochloa psedoarundinaceae), hitam (Gigantochloa atroviolaceae), dan tali (Gigantochloa apus). Pengujian sifat mekanis yang dilakukan meliputi tekan sejajar serat, tarik sejajar serat, geser sejajar serat, lentur tegak lurus serat, dan tarik tegak lurus serat. Hasil penelitian menunjukkan nilai rata-rata pengujian sifat mekanis bambu kondisi kering lebih tinggi dibandingkan kondisi basah. Nilai faktor temperatur (Ct) secara empiris kondisi kering lebih besar dibandingkan SNI 7973:2013. Sementara nilai Ct kondisi basah masih terdapat nilai yang lebih kecil daripada SNI 7973:2013. Nilai Ct empiris yang lebih besar daripada SNI 7973:2013 memiliki kemungkinan bahaya rubuh yang kecil, sehingga masih aman digunakan sebagai faktor koreksi nilai desain acuan bambu.

The physical and mechanical properties of bamboo should be measured if bamboo is used as construction materials. Bamboo for exterior construction tends to be associated with changing environmental conditions and daily temperature differences, so the temperature factor is needed to consider safety and reduce the risk of failure hazards. This study aims to compare the physical and mechanical properties of bamboo that accepts various temperatures in dry and wet conditions. The study also calculated the temperature factor (Ct) of bamboo empirically in dry and wet conditions and compared its value with SNI 7973:2013. The temperature factor (Ct) is used as an allowable stress adjustment factor in the construction structural analysis that receive temperatures hotter than the room temperature. The temperature factor value (Ct) was obtained as the ratio of the mechanical properties of bamboo in wet and dry conditions that received certain temperatures (0 °C, 38 °C, 45 °C, and 60 °C) compared to the mechanical properties under standard conditions (dry at 38 C). This study used three bamboo species, namely andong (Gigantochloa psedoarundinaceae), hitam (Gigantochloa atroviolaceae), and tali (Gigantochloa apus). The mechanical properties tests carried out include compression parallel to the fiber, tensile parallel to the fiber, shearing parallel to the fiber, bending perpendicular to the fiber, and tensile perpendicular to the fiber. The results showed that the average value of the mechanical properties of bamboo in dry conditions was higher than in wet conditions. The value of the temperature factor (Ct) empirically in dry conditions is greater than SNI 7973:2013. Meanwhile, the value of Ct in wet conditions is still smaller than SNI 7973:2013. The empirical Ct value which is greater than SNI 7973:2013 has a small possibility of failure hazard, so it is still safe to use as a correction factor for the reference design value of bamboo.