| This experiment used two kinds of adhesive to make Chinese fir glulams. Thenwe tested the creep behavior of each glulam under two different conditions, one ofwhich was high temperature and humidity, the other was common condition. We canreach the conclusion after analyzing the result:(1)The glulam, which was made by MDI and PVE, cracked easily during thelater experiment under the condition of high temperature and humidity.(2)From the fitted curves and errors, we could conclude that the burger modeldescribed the creep behavior of glulams well, especially for the glulam which wasnot cracked.(3)The instantaneous elastic behavior of glulams using the same adhesivedecreased with the increasing hight of glulams. Under the condition of hightemperature and humidity, the instantaneous elastic behavior of most glulams wasbigger than the elastic after effect. For the glulams of same hight and structure, whenusing RPF, the instantaneous elastic behavior was smaller than the glulam usingMDI.(4)The creep behavior of all glulams didn't increase all the time. There weremany jumping points. But under the effect of pressure, the whole behavior tended tobe increscent.(5)The behavior of glulams under common condition was the same as thebehavior of wood materials. The elastic after effect under common condition wassmaller than that under the condition of high temperature and humidity.(6)The speed of behavior under common condition was slower than the speedunder the condition of high temperature and humidity, especially for the first part.After unloading weight, the instantaneous elastic comeback of glulam using RPFwas almost the same as the first instantaneous elastic behavior. But the instantaneouselastic comeback of glulam using MDI was smaller than the fisrt one, because somepart of behavior could not come back.(7)The glulam made by Chinese fir and RPF had a certain carrying capacityunder the condition of high temperature and humidity. |
PDF Full Text Request