System and method for 3d construction printing

Abstract

A large-scale additive manufacturing system for printing a structure includes an extrusion system and a knitting system. The extrusion system includes a nozzle configured to receive a supply of structural material and to selectively dispense the structural material in flowable form, and a first gantry configured to move the nozzle along toolpaths defined according to a structure to be printed such that structural material may be dispensed along the toolpaths to print a series of structural layers, wherein the series of structural layers bond together to form all or a portion of the structure. The knitting system includes a tow feeder configured to feed a supply of tow material to a location proximate a current course of loops extending above an upper surface of a current structural layer or extending above a base surface in regions where no structural layer has been printed, and a hooking device configured to engage the tow material and bring it through the current course of loops to form a subsequent course of loops interwoven with the current course of loops. A controller is configured to operate the knitting system to form additional subsequent courses of loops each interwoven with a current course of loops after each of the series of structural layers are printed, wherein the interwoven courses of loops create a reinforcement network of knitted loops embedded in the structure, and wherein the series of structural layers are tied together.