[Haichuan Civil Engineering Construction Issues] Is steel rebar or plastic better for shims?

Thread Content

There are a wide variety of methods for making horse stools: some use rebar, others stone or concrete blocks, some plastic, some angle iron, some are welded together, and so on – the possibilities are endless. Some unregulated construction firms, in an effort to save on rebar, use other hard materials such as stones, shims, wooden blocks, plastic, etc. instead of stirrups to serve that function; this creates weak points in the components, affects their load-bearing capacity, and can also lead to issues such as water seepage within the slabs. The traditional approach is to make the horse stools from scrap rebar on site; of course, when a large quantity is needed, they are also fabricated from raw rebar. In modern construction, in addition to steel shims, there are many alternative methods available, such as plastic shims; one of these costs only about 0.5 yuan, and the price is even lower when purchased in large quantities. For a rebar stirrup with a diameter of 10 mm and a length of 800 mm, and at a rebar price of around 4,000 yuan per ton, the material cost alone amounts to 1.97 yuan. The disadvantage of plastic shims is that the strength of plastic is lower than that of concrete, and the adhesion between plastic and concrete is poor; as a result, the locations where these plastic shims are placed become weak points in the concrete’s strength, affecting the safety of the main structure. If not installed properly, it is also prone to leakage; therefore, plastic shims are not the best choice.