In several tests, the IKT - Institute for Underground Infrastructure has proven that the monolithic manhole base made of acid-resistant high-performance concrete from the Betonwerk Bieren concrete plant is at least as efficient as a clinker manhole base.
The investigation program included: The determination of the wear resistance of the monolithic acid-resistant high-performance concrete hardened in the mold as well as the manually made clinker channel in accordance with DIN EN 295-3; the test and evaluation of the resistance to biogenic sulphuric acid attacks in accordance with DIN 19573, Annex A, using test specimens made of the acid-resistant high-performance concrete and the joint screed for making the clinker channel, as well as testing of the material parameters compressive strength and the tensile splitting strength, and the water penetration depth using a test specimen of the high-performance concrete and the joint screed for the clinker channel.
High precision manufacturing
According to the IKT, the in-mold hardened manhole bases which are made of acid-resistant high-performance concrete from Betonwerk Bieren in a monolithic design show a higher performance than manhole bases with clinker channel in respect of the characteristics tested by IKT. The tests were conducted in accordance with DIN EN 1917/DIN V 4034-1 and according to the FBS quality guideline. The test report is available for download at www.bit.ly/p06519-schachtunterteil.
According the manufacturer Betonwerk Bieren, the manhole bases made of acid-resistant high-performance concrete moreover feature the following favorable characteristics: Manufacturing takes place in an optimized process with high precision and lower influence of workmanship on the quality than in case of manholes with clinker channel. The length of time from placing an order for the manhole to the delivery to the construction site is shorter than in case of an order for manhole bases with clinker channel. The channel is hydraulically calculated and automatically milled; it is also possible to realize complex channel exchanges in a flow optimized manner. There is only a change in material between the manhole and the sealing elements.