chutes may be provided for filling of the slipform assemblies also shown in fig2 and 3 are rolls of fabric 100 102 connected with the top and sides respectively of the frame by unrolling the fabric 104 which preferably comprises a thermal insulating material the frame can be enclosed by side and top walls to define a chamber within which slipforming can proceed in inclement weather a heater 106 fig2 is mounted on the frame to supply heat to the interior of the chamber referring now to fig4 one end of a slipform assembly 22 is shown in detail a form adjustment mechanism 36 is connected with the forms 24 of the slipform assembly the adjustment mechanism includes a pair of chocks 38 connected with the forms respectively via upper brackets 40 and lower brackets 42 a lateral displacement assembly such as a screw mechanism 44 is provided between the chocks and is operable to draft or tilt the chocks and thus the forms out of parallel in order to minimize friction between the concrete and the surfaces of each form friction between the concrete and the form surfaces is further minimized by coating the form surfaces with a layer of synthetic plastic material 46 as shown in fig5 the adjustment mechanism 36 can also be used to laterally displace the forms of each slipform assembly to increase or decrease the spacing between the forms thereby to increase or decrease the thickness of the.