Reinforced concrete is a material in which steel reinforcement. And concrete are combined into a single whole. Concrete partially protects the reinforcement metal from corrosion and perceives compressive stresses in this composite, and the reinforcement – tensile forces: it is known that metal works well in tension, and a relatively fragile concrete paver molds stone – in compression.
Today, plastic concrete with polymer additives, which appears in articles as decorative concrete, is rapidly gaining popularity. This name is determined by its great capabilities, unlike ordinary concrete: low fluidity, high stickiness and ease of artistic processing.
These properties are similar to those of decorative cement-based plaster. By the way, many enthusiasts add a small amount of it to the cement mixture to give the concrete the appropriate plasticity. How effective this is can be read in the article on this topic. Many garden lovers want to additionally decorate it with their works related to the manufacture of decorative stone. It can be tiles for paths and platforms, vases and flowerpots for flowers, as well as simple garden figurines. To use decorative concrete in your work, you need to familiarize yourself a little with its composition and manufacturing technology.
For the shape and fittings of future small architectural forms, basins, worn-out car tires, old buckets of various sizes are used. To obtain an unusual light shape, used clothes or thick cloth soaked in cement mortar are used. Thus, you can make original concrete vases that will not be afraid of the effects of our unfavorable weather (especially in winter).
How are reinforced concrete products (concrete goods) made?
Floor slabs (hollow and ribbed), lintels, elements of fences, basements and foundations. Pavement slabs, details of wells and lighting poles are all reinforced concrete products. It is obvious that each reinforced concrete product has its characteristic reinforcement system, concrete formulation and manufacturing technology. And fixed in a taut position on the mold side equipment. With the introduction of void formers or on conveyor lines. Including by means of rolling or roller molding.
The purpose of heat treatment is to accelerate concrete hardening, and after 8..12 hours of steaming at an ambient temperature of 80..95 ° C, the product gains 65..75% of its branded strength, equivalent to 28 days of hardening in natural conditions.
What not to do when installing concrete products
Any construction product, including reinforced concrete products. For reinforced concrete products working in bending, building codes and regulations have established normative permissible loads. Let’s make a reservation right away that the magnitude of these loads provides a very, very significant safety margin and, with the correct installation of the structure, the destruction of a reinforced concrete product is practically impossible. Very often it becomes necessary to make a hole in the floor panel. Such a damaged panel will not meet the load rating scale.
If it is still necessary to make a hole in the panel, then it is necessary to provide for cantilever fastening of the cut panels to intermediate support (for example, to an internal load-bearing wall or to a lintel). And perform a strapping from a metal profile along the perimeter of the cut part of the slab with fastening (threaded or welded) on this profile of the ends of the reinforcing bars.
On the delivery and intermediate storage of concrete products
And it depends only on the consumers themselves whether this reliability will decrease in the future. Concrete products, before they enter the structure and take their intended place. In addition, concrete is susceptible to biological corrosion (the appearance of mold, mildew, etc.).
Damage to concrete products can occur both during their transportation (delivery) and during their storage (intermediate storage). Moisture usually enters the products upon contact with the ground (capillary suction) or precipitation. Which can lead to both a deterioration in the mechanical characteristics of concrete products and the development of corrosive microflora on it. The most common type of damage is mechanical.
As a result, the products arrived at the facility deformed: with cracks opening more than 1 mm wide along the bottom, with concrete spalling and exposed reinforcement.
If this happened due to the fault of the supplier.
But suppliers, as a rule, comply with the conditions of carriage and such situations practically do not arise. But when reinforced concrete products arrive at the intermediate storage site. The owner himself must take care of the reinforced concrete products belonging to him. Certain “comfortable” storage conditions must be provided for them.
There should be no contact between reinforced concrete products and the ground; it is desirable to have a canopy or a film covering the product. It is advisable to store the floor slabs horizontally (in the “working position”). Laying them between themselves with wooden blocks for ventilation and to relieve the resulting stresses.
Defects, explicit and implicit
Sometimes concrete products with obvious defects are included in the purchased batch. Some of these defects are easily removable and cannot affect the quality of reinforced concrete products, some are unrecoverable and have a “lethal” nature. Sometimes defects are of a factory origin, sometimes they arise during the self-removal of concrete products as a result of their incorrect transportation.
If concrete goods are not externally destroyed, but only small chips are present. Then they are quite easily eliminated by sealing them with cement-sand mortar or special repair mixtures. If the defect is serious (displacement of the reinforcing cage, incorrect anchoring of embedded parts and mounting loops, a thin protective layer of concrete). Some factory defects (for example, a network of superficial thin cracks on the floor slab) are not “lethal” and do not affect the reliability and bearing capacity of concrete products.
