This application relates to a composite structural member comprising a portion A, a portion B, and a portion C or / and a portion H. The portion A is a
solid device having one or more cavities; the portion B is located within at least one cavity; or / and portions B and C are located within at least one cavity. The portion B comprises one or more solidifiable materials. The portion C comprises one or more restraining devices, the restraining devices enclose or enclose a spatial region, the portion B material is located within the region, and a connecting passage exists between the internal region of the restraining device and the external region of the restraining device. The portion H is a
solid device, the device encloses an outer cavity A, the outer cavity A is located outside the outer surface of the portion A, the outer cavity A contains at least one solidifiable material, and the outer cavity A has a connecting passage to at least one cavity of the portion A.