Hana Hasníková

Complex Comparative Tests on Historic Stone

This paper presents an abbreviated review of the potential capacities of the project on Non-destructive and Considerately (Medium) Destructive Methods for Testing Historic Stone, developed within the 7th EC FP STONECORE project. These methods include ultrasonic tests, peeling tests, drilling resistance and water uptake by various approaches. The material characteristics acquired by means of these methods are compared with the characteristics measured by destructive standard tests, and the observed correlations are discussed.

Structural assessment of a lapped scarf joint applied to historical timber constructions in central Europe

ABSTRACT The article deals with assessment of suitable applications of all-wooden lapped scarf joints intended for use in retrofitting of existing historical timber structures in Central Europe. The first part of the article addresses the bearing capacity and stiffness of a lapped scarf joint. In the second part, four types of roof structures typical for the region were analyzed and potential application of the joints is discussed. The third part of the article describes the influence of the application of the lap joints on the force distribution of the repaired structure, since lower stiffness of one member induces forces elsewhere in the structure as it is transmitted by the other members to the rest of the structure. Extent and influence of the stiffness change on the force distribution is briefly discussed.

Lapped scarf joints for repairs of historical structures

Jiří Kunecký Hana Hasníková Michal Kloiber Václav Sebera Jan Tippner This paper presents a description of the repair of timber structures using a prosthesis scarf joint designed for the replacement of damaged parts of beams. This new scarf joint makes use of the strutting effect of inclined contact faces where the forces are transmitted through wooden coupling elements wooden pins or dowels. The scarf can be modified in four variants according to the relevant stress and is suitable for historically valuable timber structures. It meets both functional and aesthetic requirements. The designer structural engineer will learn in the methods the loading capacity or stiffness of the beam with the designed joint, its recommended dimensions and detailed geometry. The contractor will appreciate the description of the execution and maintenance of the joint. .

New Design Method for Lap Scarf Joint Used for Reconstruction of Timber Structures

The article describes a development of a new carpentry join suitable for reconstructions of timber structures; it is possible to replace only damaged parts of wooden beam with help of the joint. The mechanical behavior of the joint was analyzed in details. The inclined faces transfer the direction of loading and use of less stiff wooden dowels allows better distribution of stresses. The design methodic has been created so that the maximum of joint potential is used safely.