Abstract
The deflection of rice seedling mats was studied as a measure of physical properties of them. In this study a part of physical properties, deflection properties, of rice seedling mats could be grasped by the use of a creep test subjected to dead load and a continuous loading test subjected to concentrated load at the center of the span. The kinds of bed soil, the planting rate and the days for raising of seedling were considered as experimental factors and changed to several levels to vary qualities of rice seedling mats provided for tests.
1) The two types of deflection test, one of them was simply supported at the opposite ends of a mat with the dead load and the others were built in at the opposite ends of a mat with the concentrated load at the center, were treated as easy methods to estimate the mechanical strength of rice seedling mats by the comparison with the deflection at the center of a certain span. It seems that the latter test gives an accurate estimation to the mechanical strength.
2) The deflection of rice seedling mats have little change in the measuring duration (within three minutes) either above-mentioned method (cf. Fig. 2).
3) The deflection of rice seedling mats was plastic, as shown in. Fig. 4 and 7.
4) The deflection of rice seedling mats was influenced by the conditions for raising of seedling, the kinds of bed soil, the planting rate, the days for raising of seedling, the weight of roots, the water content of mat and so on.
