Elina Barone

The unstable global security situation is generating demand for building construction solutions that offer enhanced protection. The methodology developed in this study allows the prediction of the thickness of glued laminated timber walls for protection classes BR1 and BR2 (9 x 19 mm Parabellum FMJ calibre) according to standard EN 1063. Material-dependent parameters have been determined for these classes, supplementing the database of ballistic characteristics for spruce CLT and birch plywood materials. The developed methodology allows for a full-scale experimental process, thereby reducing financial investment and accelerating the building design process.

Nestabilā globālā drošības situācija rada pieprasījumu pēc būvkonstrukciju risinājumiem ar paaugstinātu aizsardzību pret ārējiem draudiem. Pētījumā izstrādātā metodoloģija ļauj prognozēt līmētas koksnes sienas biezumu BR1, BR2 (kalibrs 9 mm x19 mm Parabellum FMJ) aizsardzības klasēm pēc EN 1063 standarta. Šīm klasēm noteikti no materiāla atkarīgi parametri, papildinot egles CLT un bērza saplākšņa materiālu ballistisko raksturojumu datubāzi. Izstrādātā metodoloģija ļauj prognozēt nepieciešamo ložu drošo koksnes sienas biezumu bez pilna procesa eksperimenta veikšanas, tā samazinot finansiālos ieguldījumus un paātrinot ēku projektēšanas laiku.

The authors propose a handgun bulletproof load-bearing 140 mm cross-laminated timber (CLT) wall with knitted aramid (Kevlar) fabric in two layers for tangling the bullet and a reference wall without a Kevlar layer. The study compares the layers in which the added aramid sheet should be placed for northern areas to allow people to have acceptable insulated conditions in temporary houses while being protected from potential bullet external threats. Results showed that a 140 mm CLT layer with 200 mm mineral wool insulation with a Kevlar layer between the insulation layer and CLT is enough to stop the bullet if fired up to 341.6 m/s with a firearm. Perforation data for CLT material samples with various thicknesses have been collected and analyzed. A metal rod and a ruler determined the penetration depth for ogive-nose projectiles when they did not fully perforate the panel. The results show the ballistic properties of CLT material. The results will be proposed to the construction industry of wooden buildings as a bonus for those whose security is significant.

Human security remains a topical issue, especially on the country borders where temporary houses are often used. Optimally, people should be provided with ordinary, habitable, easy-to-build, possibly portable buildings and ballistically protected. However, there is a lack of studies addressing ballistic building materials for the walls. In the scope of this study, ten ballistic materials: sand walls, concrete, steel plates, ceramic, glass fibreboards, wood (plywood, cross-laminated timber), ultra-high molecular weight polyethylene (UHMWPE) boards, aramid boards, carbon fibre boards, and gypsum plasterboard are reviewed, and their wall constructions are compared. This paper aimed to analyse bulletproof materials and to nominate the best bulletproof walls according to three required aspects - price, thermal transmittance, and weight. This is a review article that could help stakeholders to choose the appropriate ballistic material for high-risk applications.

In this study, bullet-proof building panels are investigated. The aim of this work is to verify whether the polyethylene-plywood panels withstand frontal impact with high-speed projectiles. Ultra-high molecular weight polyethylene (UHMWPE) is a promising ballistic material due to its favorable properties – significant impact toughness and a high strength-to-weight ratio, meantime it is lightweight. By setting different parameters such as laminated plywood width and various UWHMPE facade layers, the protective effect of the panels and their performance characteristics are discussed using a 9 mm caliber handgun Glock 17 Luger bullets. The results show positive results – 3 of 4 combinations resist the bullet. The board with an arrangement of 2x32 cm laminated plywood outside and UHMWPE material inside the room captures 4 bullets; the bullets pass through the plywood layer and stop in the polyethylene. The experiment also tested individual UHMWPE panels at 2 different thicknesses to monitor the damage to the material. The results of this study will be useful in designing ballistic panels for buildings like unclassified buildings (army headquarters, safe rooms) from small arms weapons also for individual use.

The growing terrorism threats across the world play an important role in the design of civil buildings and living areas. The safety of personnel is a top priority in unclassified buildings, especially military buildings. However indoor air quality and thermal comfort has a direct impact on personal productivity and ability to concentrate on duties and affect the decision making in stress conditions. The use of wooden structures is becoming more common in the building construction, and application of wooden frame structures for the construction of new buildings as well as for retrofitting the existing buildings. Prefabricated wooded frame construction perfectly fits need of unclassified buildings, allowing significant reduction of construction time and integration of various active and passive elements, such as a fresh air supply duct. Within the scope of this paper a 12 mm thick ballistic panel made of aramid was tested. Ballistic panel, thermal conductivity, and fire resistance of wooded construction panel with embedded air duct were analyzed for the various modelled exterior wall solutions. The main advantage of the proposed technology is fast and qualitative modular construction of unclassified buildings, providing all modern requirements not only for safety, but also for the energy efficiency and indoor air quality. It was found that bullet proof aramid panels do not reduce overall fire safety in comparison to traditional construction materials. However embedded outdoor air supply ducts significantly reduces construction heat transfer coefficient.