Author

ZIEGERT, C. and MÜLLER, U.
BAM Federal Institute for Materials Research and Testing, Division VII.
RÖHLEN, U.
Claytec e. K., Distribution and Technology

Abstract

The experience with the application of earth blocks in construction reaches back for several thousand years. For the last 25 years earth blocks are being increasingly used in Germany for load bearing masonry and as infilling of modern timber frame structures.
From the legal point of view earth blocks are covered by the national guideline [1] of the German Association for Building with Earth (Dachverband Lehm e.V.) which is acknowledged by our approval authority for building materials (Deutschen Institut für Bautechnik, DIBt). However, in the approval codes of the DIBt earth blocks (with other earthen materials) are ranked as building products of lesser significance (Bauregelliste C). The materials listed in this category actually are not covered by legally binding national or international standards. Due to the increased market share of earth blocks and earthen building products in general, in 2007 the DIBt suggested strongly to initiate soon a standardization process for earthen materials.
In the framework of a nationally funded project with the acronym ‘StandardLehm’ with BAM and the SME Claytec e.K. as project partners and the Dachverband Lehm e.V. as associated partner, technical guidelines for testing earthen materials are being elaborated. The guidelines are drafted in the same style as DIN standards and are intended as drafts for the future standardization process. The guidelines include earth blocks, earthen mortars and earthen plasters. For earth blocks an elaborate testing program was developed, which include the determination of the following properties:

Compressive strength

Deformation behavior (modulus of elasticity)

Water exposure resistance

Frost resistance.

Key words
standardization, earth blocks, testing procedures