IKT – Institute for Underground Infrastructure

What Goes Back Into the Sewer Trench? – Flowable Backfill Materials Put to the Test

Settlement damage, uneven bedding, and poor re-excavation capability – these are common issues on sewer construction sites. Often, the cause lies in the backfill. Temporarily Flowable Self-Compacting Backfill (TFSB) materials promise better performance – but which ones actually deliver? We tested five different TFSB products in full-scale sewer trench simulations. The aim: to evaluate how these materials perform under realistic construction conditions.