PERILAKU MEKANIK BALOK BAMBU LAMINASI DENGAN PEREKAT PATI SAGU

Bamboo was difficult to use because of its rounded shapes, unequal sizes and non homogeneous strength. One of the method to use bamboo is by making laminated bamboo so that it can be shaped into beam or plate. The laminated bamboo were made of Petung bamboo and used adhesives from sago starch and urea formaldehyde. Some consideration choosing sago starch as the adhesives is because formaldehyde-based adhesives was harmful for human health and sago starch is one of many types of starch which has high starch content besides maize. Preliminary test was needed to do before making laminated beams. This preliminary testing is intended to determine physical and mechanical properties of Petung bamboo. The major specimens of laminated bamboo beam's size were 80 mm width, 120 mm height and 3000 mm length glued by starch and UA-125 adhesives and performed in 3 repetitions. The additional specimens of laminated bamboo beam's size were 40 mm width, 50 mm height and 1500 mm length glued by starch adhesives. All of the specimens was tested for flexural as simplysupported- beams and loaded in two-point-loading system. The average result of preliminary test are as follows: moisture content 10.06%, density 0.64 gr/cm 3 , compressive strength parallel to grain of bamboo intact 79.84 MPa, compressive strength parallel to grain of bamboo strip 53.98 MPa, compressive strength perpendicular to grain of bamboo strip's outter part 87.66 MPa, compressive strength perpendicular to grain of bamboo strip's inner part 17.15 MPa, compressive strength perpendicular to grain of bamboo strip's side 15.80 MPa, tensile strength parallel to grain of bamboo strip without nodia 251.97 MPa, tensile strength parallel to grain of bamboo strip with nodia 62.97 MPa, Modulus of Rupture (MOR) of bamboo strip's outter part 164.45 MPa, MOR of bamboo strip's inner part 176.30 MPa, Modulus of Elasticity (MOE) of bamboo strip's outter part 18649.21 MPa, MOE of bamboo strip's inner part 25876.79 MPa. The average result of major specimens of laminated beams using UA-125 adhesives for MOR, MOE, shear strength parallel to glue lines and split tensile strength respectively are 158.22 MPa, 36412.81 MPa, 2.91 MPa, and 0.75 MPa. The average result of major specimens of laminated beams using sago starch adhesives for MOR, MOE, shear strength parallel to glue lines and split tensile strength respectively are 24.13 MPa, 24375.32 MPa, 3.24 MPa, and 0.30 MPa. The average result of additional specimens of laminated beams using sago starch adhesives for MOR, MOE, and shear strength parallel to glue lines respectively are 116.87 MPa, 36592.56 MPa, and 4.60 MPa. Based on these test results, it can be concluded that the strength of additional laminated beams using sago starch adhesives can be compared with the strength of major laminated beams using UA-125 as its adhesives