concrete top on firebox?

[atcnick]

I've seen several pictures and videos of people pouring a concrete top for the firebox portion of the smokehouse. From my understanding normal concrete wont be able to withstand the temperatures. What are you guys using? Or are you mixing something else with it? Or is it an issue at all? I do notice they use rebar in the forms. Thanks

 

[DanMcG]

Maybe refractory cement or something like this from lowes?

https://www.lowes.com/pd/Sakrete-50-lb-Gray-Type-High-Heat-Mortar-Mix/1000250707?cm_mmc=shp-_-c-_-prd-_-bdm-_-google-_-lia-_-210-_-masonrybaggedgoodsrepair-_-1000250707-_-0&placeholder=null&ds_rl=1286981&gclid=Cj0KCQiA_qD_BRDiARIsANjZ2LBLGTNk_G-5GZ-KxQeFrOJdUCInhcWmCvLmUo3AnxXV1C_mi4PLOFsaAuC6EALw_wcB&gclsrc=aw.ds

 

[archeryrob]

Rebar https://archeryrob.wordpress.com/2015/11/29/the-smokehouse-part-2-firebox-and-base/