I took with me a copy of "Pyramid Construction, New Evidence Discovered at Giza" by Zahi Hawass. It appeared in "Beitrage zur Kulturgeschichte Agyptens; Rainer Stadelmann" 1998. This is just about the section on ramps.
III. 2. The Discovery of the Ramp.
During the work of relocating the Sound and Light Show cables at Giza, we were able to excavate their route beginning at the Southwest of the Great Pyramid.
Also at this time we started the re-excavation of the cemetery GIS and the restoration of the tombs there.
As was discussed above the only possible side for the erection of the ramp during the reign of Khufu was the South side. The ramp was constructed of limestone chips, gypsum, and a calcareous clay called Tafla. Due to the hardiness of the construction materials what remains of the ramp, after the Egyptians removed it to build the tombs of GIS, should still exist on the South side.
We started to remove sand for the erection of the cables North of the paved road and South of the pyramid. During the work we found a big part of the ramp used to transport the stones from the quarry to the pyramid base. This part of the ramp consisted of two walls built of stone rubble and mixed with Tafla. The area in between was filled with sand and gypsum forming the bulk of the ramp (figs 3-5, pl. 3b,4a).
The length of the West wall is 1.40m, built of a stone rubble and Tafla. The maximum height is 60cm. Mud was used to consolidate the stones.
The Eastern Wall is located about 1.50m to the east of the west wall. The width is 1.45m and it is also built of stone rubble.
On the South side of the paved road, South of Khufu's pyramid, we excavated down about 2.50m and found another part of the ramp. This part is in line with the Eastern and Western wall and is of similar construction. This discovery proves that the ramp led from the quarry to the Southwest corner of the pyramid and was made of stone rubble and Tafla.
The ramp rises to about 30ms above the pyramid's base at its Southwest corner (fig 6). The ramp would have leaned against the pyramid's faces as they rose. Somewhat like accretion layers wrapped around the pyramid with a roadway on top. The weight of this ramp is borne by the ground around the pyramid. Traffic could move along the top of this structure as both pyramid and ramp rose in tandem. The top of the pyramid could be reached with only one and one quarter turns. The slope would rise with each turn from a reasonable 65°, for the first section, to as much as 18° for the last climb to the apex.
And here's the photos which aren't brilliant as I scanned from a photocopy. It doesn't help that the original captions are wrong as G1c has nothing to do with it and the ramps are at the South-West corner not the South-East:
I did my best to replicate the photos but the area has obviously been back filled since the excavation so there's not a lot to see now:
This ramp should not be confused with the one previously described by Lehner which is on the South-Corner. He describes it as:
"East of Khufu's pyramid and south of the queen's pyramids and mastabas in the Eastern Field, archaeologists from Cairo University excavated two parallel walls, formed, like so many other secondary walls at Giza, of small broken stone set in tafla clay. One of the walls is thicker and made of segments 10 cubits (5.25m or 17ft 3in) long. Because the excavators cleared the debris between them, they now describe a corridor, but we suspect that they were retaining walls - the debris fill being the body of the ramp or construction embankment." (The Complete Pyramids p.217)
Here's what that looks like: