GEOTOUR GUIDE - City of Kamloops

(sTop 11) maKinG ConCreTe and asphalT:
mosTly loCal earTh maTerials
Figure 47. A redi-mix concrete and asphalt plant, and gravel pit along Yellowhead Highway 5 at Paul Lake Road. Sand and gravel deposits are sorted
by screening into separate piles of gravel and sand, and used in the production of concrete.
Figure 48. Sand, gravel, cement, additives, and water stored in the tower are
carefully measured and mixed at the concrete redi-mix plant. (Photo by R.Turner)
Try to imagine Kamloops without concrete. There would be no highway
overpasses, home basements, building foundations, or roadside curbs.
Many tall buildings in the city centre, river bridges, and important parts
of Highway 1 through Kamloops would be missing. Now let’s imagine
Kamloops without asphalt. There would be no sealed or paved roads,
highways, or parking lots. Roads would be dusty in summer and muddy
in winter.
Hundreds of thousands of tons of concrete and asphalt are made and
used each year in the Kamloops area. What might surprise you is that the
major ingredient of our asphalt and concrete is sand and gravel from the
Kamloops area.
Concrete is the most widely used construction material globally. Twice as much concrete is used in construction than all other
building materials combined, including wood, steel, plastic and aluminum. Concrete is made by combining water with nine parts
sand and gravel and one part cement. Sand and gravel make up the bulk of concrete; cement is the glue that holds it together. To make
the cement “glue”, limestone, shale, and sand are mixed and ground to a fine powder, and then roasted at high heat. Sand and gravel
for Kamloops’ concrete is quarried from local gravel pits, while some cement is from local limestone, silica, and gypsum (Stop 10).
Asphalt is similar to concrete in that it is made primarily of local rock materials. The Paul Lake Road plant uses crushed rock from
a quarry near the Kamloops airport. However, its “glue” is liquid bitumen, a tar-like hydrocarbon related to petroleum and natural
gas. The liquid asphalt is brought to Kamloops by truck or rail car from a petroleum refinery in Vancouver.
Where does sand and gravel come from? The answer is ancient rivers. Extensive sand and gravel deposits occur below flat benches
within the valleys of the Thompson rivers. The benches are flat because they are former river beds. Gravels also occur below gently
sloping “alluvial fans” where side valleys enter the main river valleys, such as at Paul Lake Road. The sand and gravel bars of the
North Thompson and Thompson rivers, visible when river levels are low, remind us that rivers form clean gravel and sand deposits
by flushing the finer mud downstream to where it settles in the quiet waters of lakes or ocean.
How to get to tHe ConCrete and aspHalt plant: Drive north from downtown along Highway 5
and turn right on Paul Lake Road. A large sand and gravel pit and concrete and asphalt plant operation is on the north
side of the road at the intersection with Chief Louis Road. Pull off on the road shoulder and take a look. There are also
several large sand and gravel pits on Barnhartvale Road east of Kamloops.
27