Stone Arches

Ashlar and rubble masonry are best for arch construction.

Ashlar arches are constructed of stones which are cut and dressed to their true wedge shapes. Ashlar arches are used for superior work and have a good appearance. Ashlar arches can also be made to give a flat arch appearance (Fig. 19.3). These flat arches are strengthened by related or jogged joints. For excessive loads, relieving arches can be built.

Figure 19.3 Flat arch of ashlar masonry

For rubble masonry arches, roughly dressed stones are made. They are arranged and fitted into a definite arch shape using cement mortar. Because of unevenness of individual stones, the points are thicker. These arches comparatively have less strength than that one made of ashlar masonry (Fig. 19.4).

Figure 19.4 Relieving rubble masonry arch