The foundation is an important component of any structure, as it has a significant impact on the structure’s structural stability. Foundation buildings are frequently susceptible to various types of attacks from subsurface water and soils, necessitating the implementation of necessary safety measures. How Can Foundation Structures Be Protected From Soil and Ground Water Attacks?The following considerations about foundation structure attacks caused by hazardous substances in soils and ground water are explored in this article: Attacks and their causes Exploration of the soil and groundwater Protection of concrete foundation buildings from soil and ground water attacks Anti-corrosion protection for steel piling Timber piles must be protected. Attacks on Foundation Structures: What Causes Them? Various types of foundations may be subjected to various forms of attacks.
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Attacks on Foundation Structures: What Causes Them?
Determining the groundwater table, fluctuation, and presence of aggressive compounds in the soil is critical because adequate protection measures can be provided based on the site condition on which the foundation is built. Chemical analysis is usually performed on ground water, disturbed and undisturbed soil samples. Stand pipes can be installed in boreholes for an extended period of time to collect data and assess groundwater levels. Not only can the groundwater fluctuation be determined this manner, but the average groundwater level can also be acquired. To appropriately characterise sulphate content and estimate sulphate content variations as the depth is raised, enough data must be collected. This is due to the possibility that uneconomical protection measures may be adopted based on insufficient evidence.
Protecting Concrete Foundation Structures from Soil and Ground Water Infiltration the aggression of sulphate existing in soil and ground water is the primary cause of concrete foundation deterioration. Chemical wastes, organic acids, specific deleterious aggregate, reinforcement corrosion, and saltwater action, in addition to sulphate assault, could cause concrete foundation degradation. The potential protection measures that can be utilised to defend concrete foundation structures against soil and ground water attacks will be outlined in the following sections.Defend Against Sulfate Attack To safeguard a concrete foundation structure from threats, a variety of strategies can be used. Type II Portland cement has a reasonable resistance to sulphate attack, whereas Type V Portland cement has a high resistance to sulphate attack, according to ASTM classification.
Organic Acid Attacks in Soils and Groundwater:
Super-sulphate and high alumina cement can be used to combat the most serious sulphate assault from soil and ground water. Despite the fact that high alumina cement may experience conversion, which is a sudden loss of concrete compressive strength, this problem may be addressed and such concrete has residual strength when it undergoes conversion. The lowering of concrete sulphate resistance is a sign of significant alumina conversion. To minimise high alumina conversion, avoid using a high proportion of cement, protect the concrete from heat, avoid steam curing, and use suitable shading to protect concrete piles in stock yards from the sun. In places with high sulphate concentrations, suitable compaction of sulphate resistant cement may be sufficient for typical foundation construction, whereas protective measures are required in areas with low sulphate concentrations.
It is advised that plastic or bituminous sheets be used to wrap the concrete pad and strip base. Heavy-duty plastic sheeting can be used to protect cast-in-place and driven concrete piles, however fastenings can shred this protection layer. So, instead of galvanised corrugated cylindrical sheeting, steel sheeting, or rigid PVC tubing, rigid PVC tubing or galvanised corrugated cylindrical sheeting can be utilised, but it will be more expensive.Organic Acid Attacks in Soils and Groundwater: Concrete Foundation Protection Natural acids can be found in peat soils and water, and free Sulphuric acid can be generated when pyrite or marcasite is oxidised. If impermeable concrete is available, the former is less aggressive, whereas the latter is quite damaging to concrete.
Chemical and Industrial Waste Protection for Concrete Foundations
High sulphate content and pH values are utilised as indicators of the presence of free Sulphuric, and protection measures are indicated based on the pH values. For example, if the pH value is more than 6, no action is required; however, smaller values might necessitate the usage of sulphate resistant cement, rapid hardening cement, fly ash, or powdered granulated blast furnace slag to offer the requisite protection. Chemical and Industrial Waste Protection for Concrete Foundations Chemical works and discarded trash may contain hazardous chemical compounds. This material is tough to work with since chemical concentrations change and their identification is challenging.
If the construction site contains aggressive chemical substances such as acid waste, it is recommended to use a pile foundation made of a precast concrete shell with a hollow interior filled with concrete and the outer shell acting as a sacrificial over the length of the shaft in the ground contaminated with chemical wastes. Steel Piles Anti-Corrosion Protection Steel piles are susceptible to corrosion in soils and ground water, as both air and water are necessary for steel pile corrosion to occur. Certain portions of the steel pile will often act as anode locations, while others will operate as cathode areas. As a result, rust will form in cathode locations, whereas pitting will form in anode areas.
Steel Pile Paint Treatment Protection
Steel piling corrosion in soil and ground water is a severe issue that must be addressed appropriately. The recommended measures to preserve steel piles in soil and ground water from corrosion will be briefly discussed in the following sections. Paint Protection for Steel Piles In this procedure, the structure is first subjected to a sand or grit blasting treatment in order to obtain a white metal finish. After that, a zinc silicate prime coat with a thickness of 50-75 micrometres is applied to the clean metal surface. Finally, a top coat of epoxy or vinyl paint is applied. It’s important to remember that the prime coat and top coat should complement each other. Paint treatment is used to protect areas of marine structures above the waterline.
Finally, keep in mind that paint treatment is not appropriate for a structure’s lengthy service life in a splash zone. As a result, it is recommended that steel plates be installed to safeguard the structure or that the steel piles’ thickness be increased. Steel pile corrosion in a marine environment shows the corrosion of a steel piling in a sea environment. Steel Piles with Cathodic Protection The cathodic protection system is based on the use of metals’ unique electrochemical potential. The structure is turned cathodic with this approach, which prevents metals from migrating from the structure to soils, groundwater, or any other solution. Cathodic protection can be achieved via a power supply-supplied system or a sacrificial anode. Anodes are used in the first scenario.
Protection of Timber Piles
It should be noted that by keeping the exposed area of the structure to a minimum, anode waste will be reduced and power supply requirements will be reduced.In terms of sacrificial anode application, it is made up of relatively significant masses of anode metals that corrode while providing protection during the structure’s service life. As a result, sacrificial anodes may need to be replaced after a while, particularly in a marine environment. Furthermore, the electromotive series of the sacrificial anode should be bigger than the electromotive series of the structure to be protected. Finally, it is thought that using a sacrificial anode in marine structures is more viable than using a power supply because the latter requires cables that could be damaged.
you can use preventive measures like a sump pump in the basement floor and a tile drainage system.
A further effect of flooding is that of soil erosion and scour which can do significant damage to foundations.
Two principal approaches can be used: groundwater control by pumping.