Russia's experimental armour: Cement and sand in the frontline
A recently published report from the Russian research institute NII Stali indicates that Russians, struggling with significant equipment losses and a chronic lack of high-quality equipment, have decided to experiment with constructing reactive armour (ERA). They have begun adding cement and sand to it.
NII Stali, or the Scientific Research Institute of Steel, has presented an analysis concerning the experimental tests of armour, into which a mixture of sand and Portland cement was placed. Their purpose was to absorb part of the kinetic energy in the event of impact, as well as to act as an additional element to disperse explosion energy.
Cement and sand in Russian tanks
Theoretically, Russians are trying to improve the effectiveness of the cheapest and most readily available forms of vehicle protection—especially in the context of mass-produced T-62 and T-72 tanks and armoured personnel carriers. In practice, however, such “reinforcements” do not match the classic explosive charges used in modern ERA modules.
Sand and cement do not detonate and only to a limited extent dampen the impact of a projectile or shrapnel, making the whole modification at best a half-measure, and at worst, an illusion of protection. Replacing the classic equipment of ERA modules with these could turn a tank or armoured vehicle into a deadly trap for the crew. This solution not only worsens protection effectiveness but also demoralises soldiers who know that their chances of survival against modern weaponry drastically decrease.
It is also concerning that such solutions are not solely the subject of laboratory research. As experts observing the battlefield in Ukraine indicate, makeshift “concrete” armours indeed appear on Russian vehicles. Some of them are equipped with structures that closely resemble reactive armour but are actually decoys or filled with construction mixtures.
The entire situation also highlights the quality of Russian logistical supplies and the problems in providing modern components. If sand and cement are intended to replace advanced composite materials and explosive charges in ERA armour, it not only worsens protection effectiveness but also demoralises crews who know that their chances of survival against modern weapons drastically decrease.
NERA as a chance for enhancing tanks?
The currently observed crisis in Russia's armoured forces is also forcing its engineers to create new types of non-explosive reactive armour, or NERA. This modern type of armoured vehicle protection—unlike classic ERA—does not use explosive charges.
NERA works on the principle of the mechanical reaction of material layers to impact. It consists of a multi-layered structure, usually including metal plates and flexible inserts, such as rubber, plastics, or special composites. When a projectile hits this type of armour, the flexible layer between steel plates undergoes rapid compression and expansion. This causes dynamic displacement of the outer layers, which disrupts the stability of the cumulative jet or penetrator core, significantly reducing its piercing ability.
The main advantage of NERA is the absence of explosions. Such armour can be used on vehicles operating in close contact with their own units—infantry, support vehicles, or in urban environments—without fear of the side effects of detonation. It also facilitates maintenance and transportation since NERA is not classified as an explosive material.
This technology is increasingly being applied in NATO armies, and its elements can be found in, among other places, Israeli Merkava tanks, modern variants of the Abrams, and also in European projects like the Leopard 2A7. Interestingly, NERA solutions are also being developed in the Ukrainian defence industry—local engineers, based on experiences from the battlefield, are seeking effective alternatives to classic ERA, which can be unreliable when hit by drones or tandem warheads.
