Aluminum belt-discharge bodies configured for installation on frames of straight truck or trailer chassis used in construction materials hauling. The use of aluminum provides substantial weight savings, which allows for an increase in the payload that can be hauled by the truck to the paving machine. The belt bodies also feature a wider unloading belt as compared to conventional steel live-bottom trucks, which increases efficiency, reduces unloading time and generates faster cycle times. The wider bottom lowers the center of gravity of the vehicle, resulting in more stability and safety. Furthermore, a wider body with sloped side walls reduces and/or eliminates the effects of transportation segregation of the asphalt or aggregate being hauled. Belt-discharge bodies according to the invention effectively remix the material being hauled as it is unloaded.