Modular building systems

An assembly of a plurality of building modules that connect to form a structure of a modular building for modular construction of the modular building, the assembly comprising:

• a plurality of building modules, a building module of the building modules comprising:
• a deck oriented in a horizontal plane;
• a plurality of hollow structural members, wherein at least a portion of the plurality of hollow structural members are distributed around a periphery of the deck and extend downwardly from around the periphery of the deck, wherein at least the portion of the plurality of hollow structural members have receptacle ends receiving at least a portion of corresponding other hollow structural members of another building module and connect the respective building module to the other building module, wherein the hollow structural members of the respective building module connected with the other hollow structural members of the other building module receive set flowable medium that sets to a solid structural material, wherein the hollow structural members are of a rigid material to support the set flowable medium and shaped to receive the flowable medium;
• wherein at least one hollow structural member of the building module comprises a connecting component elongated along a longitudinal axis of the hollow structural member and extending from the top thereof, the connecting component to vertically connect the building module to the other building module for reinforcing a structure of the modular building;
• and
• a sealing member between two adjacent building modules, wherein the sealing member occupies a gap or space between the two adjacent building modules, wherein the two adjacent building modules can be vertically adjacent or horizontally adjacent, wherein the sealing member is compressible.