Hello,I am looking for suggestion in filling voids made by woodchucks.Specifically,a tunnel that is level open at both ends and under a concrete driveway just outside the garage door.I have considered buying a manual grout pump and bags of grout,I contacted a builder who advised mixing grout like milk for consistency and simply pouring it in one end-no need for pump.Another advised a trash pump.My main concern is filling it totally and not undermining the strength of the concrete above.I have been reading about Flowable fill and CLSM,but it appears I have to get this from a concrete ready-mix co.
are there any places to buy flowable fill by the bag,and mix with water? Thank you for any help you can offer!