The standard way of construction for pavements is non-bonded laying of elements in crushed sand/split mixtures. Under special loads and cleaning requirements this traditional, overcome construction method easily fails. The bonded construction method is neither mentioned in the German rules and standards nor embraced according to its importance. On the contrary: the wording of the former DIN 18318 was unusable as far as the characterised mortar specifications are concerned. For the new drawing up they were accordingly discarded, but astonishingly not replaced by the common state of the art.
But the German rules for road construction (pavement and slabs) are in a state of change, too. Advice and recommendations for an adapted mortar construction method (element construction method) were compiled in the form of the FSGV-Arbeitspapier Nr. 618/2 (working paper for surface pavements with pavings and slabs using bonded construction), which now reflects the current state of the art. Nevertheless, mandatory regulations are to be expected only in a few years.
In other European countries, there exist viable descriptions of adapted bonded construction methods as recommendations. Great Britain has a construction standard that prescribes the bonded construction method for heavily used streets and squares and describes the required characteristics of the mortar in detail (BS 7533, Part 7, 10 and 12). STEIN TEC® mortars fulfil and surpass these high requirements.
In particular, the “minimum joint depth” must be considered: in many cases a value of 30 mm is declared as “minimum joint depth”. This value has its origin in the out-dated DIN 18318. DIN 18318-2006 solely refers to a joint filling with permanently-elastic paving-joint compounds according to TL Fug-StB / ZTV Fug-StB. For the bonded construction method of element surfaces, 30-mm joint fillings with cement-bound mortar are usually insufficient (exception: mosaic sett pavings).
The working paper FGSV-Arbeitspapier Nr. 618/2 “Flächenbefestigungen mit Pflasterdecken und Plattenbelägen in gebundener Ausführung” (“Surface pavements with pavings and slabs by bonded construction”), published in August 2007, points out that the free joint height (space for the joint filling after imbedding) must be two thirds of the paving block or the slab thickness at the minimum, respectively. Before filling the joints, they must be cleared from dust and loose components.
Afterwards, the remaining joint space has to be completely filled up with jointing mortar to which the risen, non-compressed bedding mortar must be force-fit bound.
The production of STEIN TEC® mortars is constantly monitored internally and externally. All characteristics of practical relevance are under strict control. For example, to prove the resistiveness against frost-protection and de-icing agent (at Jointing Mortars), a freezing test in a three-per cent solution of sodium chloride is carried out. After this test, pressure resistance and sound run-time (as an unerring indicator for intact elements) must not have decreased by more than 10 per cent! This is a “relentless” examination of the suitability for long-term durability.
Please consider our above-mentioned advice about reading these pages, about wording of performance requirements and about evaluation of performance descriptions. We offer expert advice.