Gabions can be filled with soil (of course combined geotextile on sides which keeps the soil inside). They can be filled also with stones and hard timber. Although, when talking about gabions and its content it is important to know that not all stones are suitable for gabions.
We can use only stones which do not change their structure due to climate change. Rubble with life attestation of 15 years is used. When unsuitable stone is used it can cause the destruction of gabions.
What does it help us to choose suitable stone for gabions?
Like choosing suitable aggregate for gabions basket and stiffeners production is important, choosing a stone or aggregate (i.e. content of a gabion) is equally important. The stone should be chosen according to hardiness (it has to have life attestation of 15 years, it must not be splintery, hard and moisture resistant), colours, shape and size. Stone width (i.e. size) in comparison with holes of specifically chosen stell net of gabion baskets has to be taken into consideration. Size of selected stone is dependent on mesh size of nets of the gabion baskets and they have to be 1.5 – 3 times larger than the mesh. Stones of smaller size must not be chosen because they could spill out of gabion baskets which would result in their destruction. Moreover, small stones falling down from gabion baskets could put passers-by’s health in danger. Stone filler of 32 – 63 or 63 – 125 cm size is used very often.
Water absorption and frost protection
Chosen stone has to resist weather conditions. It also must not change its structure. The stone must be frost resistant and less water absorbent. The frost would tear the stone apart due to freezing of moist pores.
Water absorption of stone is the proportion by weight of water accepted by stone submerged into water at atmospheric pressure for 48 hours or it is fixing of weight towards weight of dried stone (percentages). Water absorption is directly linked to frost protection because water resistant stone resists freezing most. As for frost protection we talk about frost protection coefficient after 25 cycles and its value should be as low as possible.