Concrete is generally grouped into two categories, normal and high-strength. The variations of the normal and high-strength concrete are based on their compressive strength. Depending on the maximum resistance of a sample of concrete, the psi strength results derived from the compression test define whether the concrete is classified as normal or high-strength. If a concrete tests to have a compressive strength of more than 6,000 psi, the concrete is defined as high strength.
At International Vault, Inc., we have created a professionally custom engineered high-strength concrete mix that is used to construct our vault doors, Megacrete panels, and modular buildings. As a stronger alternative than cast-in-place and other projects using normal concrete, it is economical and will increase the overall strength and security of your system.
Water, cement, and other forms of aggregate are the main components of normal concrete. This type of concrete takes between thirty to ninety minutes to set, depending on exterior conditions such as moisture and temperature. Normal concrete is more susceptible to damage and cracking due to its lack of tension strength.
High-strength concrete is commonly accompanied by other additional aggregates than normal concrete that increase the strength and bondability of concrete particles within the mix. Carefully engineering our high-strength mix, we have achieved a precast concrete mixture that is strong, durable, lighter weight than comparable offerings for other UL 608 panels, and is cost effective. This concrete has a lower water to cement ratio than normal concrete, which increases its strength. Our concrete mix is impaction resistant, abrasion resistant, technologically advanced and durable. Other attributes include low shrinkage, low permeability, and features a high modulus of elasticity.
Our modular vault panels and vault doors are UL 608 burglary resistant, which indicates tool and torch attack resistance. The consistency in our concrete mix is of utmost importance. We stress the quality of our high-strength concrete mixture, and ensure an even spread during the pour of each vault panel and door. The concrete is given a minimum amount of time to mix, and samples are taken from each pour to ensure the consistency of each batch is correct and up to our high standards. The floors in our concrete pouring area are heated to ensure the ideal temperature for curing conditions every time.
Prior to the casting of our high-strength concrete mix, metal rails on end of panels are installed and rebar is strategically positioned within the frame. While perimeter metal rails have no burglary resistance, they act as a point of connection to weld for structural purposes and double as a match casting form. Once the panels are cast, the high-strength concrete is vibrated to reduce air particles in the concrete. The more air is present in the concrete mix, the higher chance of micro-fracturing between layers, a primary concern when using cast-in-place concrete.
There are several risks of using normal cast-in-place concrete instead of high-strength precast concrete panels. First, temperature variance could cause imperfections in the concrete ultimately leading to fracturing and weak areas. Cast-in-place concrete is also conditional among other trades. For example if the floor is not complete, there is no feasible way to build the walls and ceilings of the vault structure. Since it does rely on other trades, if the concrete arrives on site and is forced to wait for an extended period of time, water is continuously added to the mix in order to keep concrete from curing, thus weakening the chemical composition of the concrete. In addition, the arrangement of rebar in a vertical concrete form is hard to consistently and effectively place. To make sure rebar placement is accurate when using cast-in-place forms, X-Rays need to be taken of the walls to ensure the rebar is in the most efficient position. This is costly and the use of precast panels is much easier to guarantee proper placement of the rebar. Cast-in-place also creates much more of a mess than precast panels for on-site installation. Drying and curing time is another hindrance, and cast-in-place physically blocks off parts of construction due to the large size of the forms.
Creating a specific balance of heat and tool resistance materials is delicate. Materials that are great resisting heat and torch are generally brittle against tools, and vice versa. Strategically balancing materials that resist both heat and tools in a way that does not compromise the integrity or strength of the panel. Certain parts of the mix are meant to create a balance between the heat and tool resistance. Rebar placed in the panel is a tool resistant portion of the panel, an element that a torch would melt quickly, whereas the high-strength concrete’s purpose is to buy time for the rebar to preserve the overall structure of the vault.
The use of high-strength concrete panels will increase the overall security and protection of your vault system. In addition to a cleaner, quicker, and more efficient installation process, your assets will be protected by our 4 decades of precast concrete expertise.