Shear Behavior of Wheat-Concrete Interface during Monotonic and Cyclic Loading

Changnv Zeng,Yuke Wang

doi:10.1155/2019/6792650

Abstract

The interface behavior between wheat and concrete plays a decisive role in the design of silo structures. In this paper, a series of strain-controlled monotonic direct shear (MDS) tests, cyclic direct shear (CDS) tests, and postcyclic direct shear (PCDS) tests were conducted to investigate the wheat-concrete interface behavior under monotonic and cyclic loading. The influence of cycle numbers, shear displacement amplitude, normal stress, and preloading consolidation was discussed in detail. In particular, the preloading consolidation simulates the partly discharging state of wheat. The values of peak stress increase with increasing displacement amplitude and cycles, and they change slightly after 10 cycles. The interface exhibits an overall contraction deformation during the MDS tests without preloading, but the contraction is suppressed by an alternating dilation during the DCS tests, and an overall small dilation occurs at small normal stress during PCDS tests. It is observed that the cyclic loading and preloading normal stresses result in an increasing peak strength, internal friction angle, and apparent cohesion, whereas a decrease in interface contraction deformation.

Highlights

Monotonic Behavior of Wheat-Concrete Interface. e development of horizontal shear stress and vertical displacement with horizontal shear displacement of wheatconcrete interface is shown in Figure 4 for monotonic direct shear (MDS) tests
The imposed constant normal stresses are 50 kPa, 100 kPa, and 150 kPa, respectively. e wheat sample with a void ratio of 0.532 was poured into the upper shear box, while the concrete block is placed into the lower half. e tests with a preloading of 200 kPa is considered compared with those applied by constant normal stress of 50 kPa, 100 kPa, and 150 kPa, respectively, which simulates partly unloaded condition during the storage
Even some dilative behaviors were seen in the postcyclic direct shear (PCDS) test, whereas the overall contraction occurred during the MDS test

Summary

Materials and Methods

E test sample was prepared by pouring wheat into the upper box in 5 layers with the specified mass of wheat, while the concrete plate was put into the lower shear box.

Test Results

Cyclic and Postcyclic Behavior of Wheat-Concrete Interface

Discussion