1. Scope 1.1 This specification covers single-cell pre-cast reinforced concrete box sections intended to be used for the construction of culverts and for the conveyance of storm water, industrial wastes, and sewage. 1.2 This metric specification is equivalent to C789 and is compatible in technical content. Note 1-This specification is primarily a manufacturing and purchasing specification. However, standard designs are included and the criteria used to develop these designs are given in the Appendixes. The successful performance of this product depends upon the proper selection of the box section, bedding, backfill, and care that the installation conforms to the construction specifications. The owner of the precast reinforced concrete box sections specified herein is cautioned that he must properly correlate the loading conditions and the field requirements with the box section specified and provide inspection at the construction site. Note 2-Specification C850M is to be used for box sections with less than 0.6 m of cover subjected to highway loading.