Loffelstein Retaining System

Rainbow Concrete is manufacturing the Loffelstein Retaining System in Bloemfontein as a franchisee of Infraset.

The dry stacking, interlocking, retaining system. Unique of its versatility, adaptability and plantability.
- Structurally stable – no need for additional concrete infill
- Ideally suited for retaining cut or fill slopes between 3 and 15m in height
- Two basic block sizes – L300/L500.

Foundations – must be designed to suit individual projects. In most instances a simple concrete foundation will suffice.

Laying – at 180mm spacing, lay the first course of blocks on the level base/angled base. Interlocking blocks of the second course are then centrally stacked to span two blocks of the lower course. Align the blocks horizontally with a straight edge spirit level. Adjust minor level variations in blocks by trimming the higher sides with a chipping hammer, or lifting the lower side and packing stabilized soil underneath. Align long straight lengths of wailing by securing a fish line around outermost lying blocks and pulling the face of each block almost against the line. Fill preceding blocks with a suitable plant supportive soil. Compaction behind the blocks is critical.

Curvatures – with the smallest possible radius of 2m for L300 and 3m for L500. Convex curvatures get smaller as an inclined structure rises. The first course is laid out to a maximum spacing of 190mm in the front and a corresponding smaller spacing at the back to suit the required radius. Concave curvatures get bigger as you build an inclined structure. Therefore, the first course is laid out with a spacing between the backs of the blocks. Depending on the accuracy of laying and the actual layout of curvatures, you may experience difficulties with the interlock or spacing of blocks after erecting four or five courses. To rectify this you should fill the completed preceding row of blocks with soil, tamper down hard and reset in accordance with the first course’s layout. Engineered designs – before construction consider soil conditions, cohesion of material, overall slope stability, foundation requirements and choice of reinforcement.

Planting – completed structure. Take care in the choice of plants, in order to minimise possible maintenance problems. Indigenous ground covers are recommended.

Technical advice – the structural stability of a gravity retaining system depends on soil conditions, wall angle, overall slope stability and slope angle (surcharge) on top of the wall and base of wall. NB – Structures exceeding designs and the submission of plans to the local authority. Note – This serves only as guidelines.