Gravimotion strong-activity (physics’ strong force) and radial-activity (physics gravitational field) make one; or physics’ strong force and gravitational field, in gravimotion, are of same constitution as explained next.

Because the force of gravity becomes mathematically infinite at distances close to zero, that mathematical force of gravity also fits physics' strong force, as both are in reality and mathematically huge at close to zero distances.
Furthermore right under our eyes is physical evidence that physics' strong force is of type gravity; at the center of our sun, 2 nuclei of hydrogen atoms (1 proton for each nucleus) are fused (locked together) into a single helium nucleus under sheer gravity force. The force of gravity at subatomic scales is obviously as strong as physics so called strong force! It is furthermore acting in the right direction toward a common center.
By the way, to be precise, 4 atoms of hydrogen are actually necessary to make an helium atom; 2 hydrogen atoms turning to neutrons in the helium nucleus.

I asked myself the question: how can physicists claim the strong force that binds protons together has nothing to do with gravity, when 2 protons in our sun are bound together by gravity?
Later (on Friday 1 Nov 2013 to be precise) I had the opportunity to ask a physicist that very same question. The answer was: the force of gravity is acting on huge distances; the strong force on the other hand is acting on close to zero distances!
All in all, an intelligent and knowledgeable physicist will not even consider the words of a question that contradicts its point of view. He will not discuss the matter.
Dear reader rest assured that I know that you do not have to share my point of view either! Any human being, a characteristic that we all share, has its own truth built its own way.

To get back to my own point of view though, is it not ironic that one objective of science is to unify the 4 forces! So that objective of science must include unifying the strong and gravity forces! And there is an effort toward that goal; the first time I read the strong force might be gravitational (in the world of physics) is in the American Scientific May 2012, Volume 306, Number 5, page 40 in which it is written the "unitary method" leads to 2 gluons being mathematically identical to 1 graviton.
The irony is in that the solution is right under our noses! Just notice that:

1. On large cosmological scales the force of gravity has the prerogative.
2. At our human molecular and atomic scales the electrical force takes over that prerogative.
3. At subatomic scales the force of gravity regains its control.

The electrical force overcoming gravity at a smaller scale (case 2/) doesn't necessarily forbid the opposite at another smaller yet scale (case 3/)!
In my book "The Harmony of Reality" published in 2008 (discontinued since), I already mentioned (page 53) the idea that the strong and gravitational force make one; and I am convinced I am not alone thinking so.
While in physics it is against Nature that the force of gravity regains control at subatomic scales, radial-activity (physics' force of gravity) taking over graded-activity (physics' electric fields) at very small distances is natural in gravimotion description of Nature; the density of motion or graded activity reaches a finite amount at the center of a subatomic particle, on the other hand the compounded motion inclination or radial-activity becomes more and more potent at ever decreasing volumes. In the gravimotion world, gravitation is exclusively motion, and not at all force.
The evidence is that free fall is motion.
Yet the sensation you and I are feeling under our feet when standing up, which is called force in physics, is restricted motion in gravimotion.

And this restricted motion (force in physics) also coincides to our weight.
Please note that figure 4.6 is a partial representation of reality, and is essentially idealized. Whether we consider the occurrence of free-fall on the left or the occurrence of restricted-motion on the right, both occurrences neglect to represent their subjacent motions that are not only occurring in the background, but also modifying or affecting the situation. Because mass doesn’t contribute to the hardness of matter (§4.2), because mass doesn’t contribute to gravity (§4.4), and because weight is not mass but restricted motion (§4.6),mass doesn’t need to exist; and for all purposes mass doesn’t exist in gravimotion.
The quantum theory, in which mass was all but forgotten to start with, was on the right track until the 1970s when physicists decided to invent a particle, now given the name Higgs boson, just to satisfy our belief that mass is physical! The Higgs boson will not be discovered, or if it is, it will nevertheless remain as fictitious as time for instance.