To ensure the carrying safety and longterm durability of nuclear waste

the tests of flexural properties were carried out respectively at normal temperature and after being heated to 150℃ using orthogonal mix proportion design and incorporating steel

polypropylene hybrid fiber

fly ash or steel fiber solely in the concrete. Based on gradation and variance analyses

different kinds of admixtures and their effects on toughness of concrete are quantified. Fiber type and incorporation can improve the mechanical properties of high performance concrete effectively after cracking

which is more remarkable after being heated. Steel fiber A with sheared threads has the best effect on anticracking and toughening at preand post heating. With the increase of fiber incorporations

the flexibility of hybrid steel fiber concrete increases basically. The hybrid steel fiber is better than steel fiber with single incorporation in flexural properties at normal temperature

but no difference after being heated.