Use of and construction method for concrete block paving in the Federal Republic of Germany

For hundreds, indeed thousands of years, the only form of road surfacing was with stone blocks. The invention of tbe internal combustion engine and the tremendous growth of motorization, in conjunction with the use of asphalt, thrust the block-paved road into the background and bad a major effect on the traffic routes in our environment, turning them into ugly features, mere uniform running tracks for traffic. It was not until people began to think in terms of the desirability of pedestrian precincts, traffic noise abatement and improvement of the residential environment that paving blocks and slabs experienced a resurgence. Planners strive deliberately to use tbese materials to signify a turning-away from conventional road construction. In the sbopping street the block paving constitutes an environmental design feature; in the motor traffic restricted zone it serves to rouse tbe motorist's awareness to his surroundings. In all municipal road and street developments in the Federal Republic of Germany the use of concrete block paving predominates in the design of motor traffic restricted zones, pedestrian precincts, footways, cycle tracks and parking strips. Because it is uncomfortable to walk on and because of difficulties associated with open joints, natural stone block paving is to be deprecated for shopping streets. On the other hand, any planner engaged in schemes for old town centres would be well advised to use at least a combination of natural stone and precast blocks. Concrete paving blocks should be laid on a bedding consisting of 0 - 2 mm or 0 - 4 mm sand, J - 3 mm or 2 - 5 mm chippings or a 0 - 5 mm mixture of crushed stone sand and chippings. A binderless sub-base of crushed stone, blastfurnace slag or recycled material on a gravel blanket course is recommended. Crushed natural stone sand is especially suitable for sealing the joints. Blocks laid in a bed of mortar on a concrete sub-base should be used only in exceptional cases because there are many instances of unfavourable experience with this form of construction. All block pavings for road construction purposes must comply with DIN 18318, which is currently being revised