The invention relates to a planar structure for joining, in particular for the material-uniting joining, of at least two components. According to the invention, the planar structure is flexible and formed by at least one reaction strand. The reaction strand comprises a preferably cylindrical core, which is provided, at least in some areas, with a coating, which is constructed with a plurality of coaxially applied layers with a small thickness. To produce the layers, two different materials are used, the layers being constructed alternately with one of the two materials. Because of the high degree of flexibility of the reactive planar structure and its arbitrary area extent, components with a complex geometry in the region of the joint faces as well as large-format components can be joined in a material-uniting manner without problems. The reactive planar structure can be produced here using the methods known from textile engineering with virtually any dimensions and, in addition, by a continuous industrial production process. Moreover, the invention relates to a method for providing a material-uniting connection between two components, in particular by means of the planar structure according to the invention.