In the urban city’s infrastructure, sidewalks are the most important elements on the roads. If these sidewalks by any chance fail prematurely then their replacement cost can be quite high. These sidewalks are generally meant for pedestrians to walk safely and comfortably.
If you take a sample data about Canada, then 15 to 20 per cent of the 100,000 kilometers of sidewalks need immediate replacement. The replacement cost is estimated to be around $1.5 to $2.4 billion. Depending upon their geographical location and also their quality of construction, the average life of these roads and the service life of these sidewalks is estimated to be anything from 20 to 40 years. In some of the Canadian cities there can be premature failure of these sideways within 1 to 5 years after their constructions that may need immediate sidewalk trip hazard repair activities.
If you consider about the sideways of the North America and its surrounding areas, you can divide them into two broad categories. One can be considered as flexible sideways while the other as rigid sideways. The majority of sideways however come under the category of rigid concrete slab. Let us therefore discuss about the reasons why these concrete sideways fail.
Usually it is quite economical to construct these concrete sidewalks. If they are constructed well, then they can look attractive and also last longer. Typically the width of the slab used is about 1.2 to 2 meter and its length is slightly greater than its width. The thickness of the slab is usually 100 to 150 mm.
If you look at the older designs then you will find that it consists of flat concrete slabs with uniform thickness. They are placed adjacent to a beam of L shape, which forms the curb and gutter and this full depth joint separates the two components.
Nowadays the designs of sidewalks are using monolithic design and in such design there are no full depth joints between curb, flat slab and the gutter. Such monolithic designs are much faster to build and also vehicles can easily access the driveways without much difficulty. The performance of both the new and old designs can be compared.
Most of the sidewalks in new subdivisions, you will find that concrete extrusion is used for constructing of sidewalks. In such way, it is possible to use native soil, compaction for the sideways and placement of all the concrete is done in a single pass.