round cover/plug for septic tanks
round cover/plug for septic tanks
(OP)
Most precast septic tanks, and other tanks have openings in their top slabs; usually 24"diameter, but some upto 48" diameter; these openings need to be covered by concrete cover/plugs same thickness as the top slab; my question is such; is there a need for circumferential reinforcing around the periphery of the cover; usually a mesh of bottom steel is satisfactory to resist H-20 loading; I am concerned about cracks forming due to shear;
a general question in this subject:
in slabs where there is no shear reinforcing how to prevent shear failure resulting from a moving truck load for example; this load will act as an impact load of magnitude 20 kips in a localized area on the slab; here slab is the top of a rectangular tank slightly ( about 8" ) buried in ground. appreciate your toughts expertis ein the above subject. thanks





RE: round cover/plug for septic tanks
I have seen diagonal (to the main orthogonal reinforcing) bars used around a circular hole. This may be a more practical solution.
Shear reinforcement is seldom used in thin (less than 150 mm = 6'') slabs, and some research has shown that shear reinforcing would be of little value. The shear strength of a thin slab is achieved by a conbination of concrete compressive strength, good aggregate interlock, and the correct amount of tensile reinforcing steel.
RE: round cover/plug for septic tanks
Can the tension steel that passes through the shear plane be used in the calculation of shear capacity?
RE: round cover/plug for septic tanks