I'm not aware of a specific list of break DCs for objects in the core rulebooks. The DMG on page 238 does give some general descriptions of DCs, stating that "A DC 25 task is very hard for low-level characters to accomplish, but it becomes more reasonable after lOth level or so." The table goes up to 30, which is described as "nearly impossible." Obviously "very hard" is pretty subjective, and is offset by your character's ability score. For your character, you basically have a possible range of 24-33 in a strength check, so 25 would probably a light amount of effort. Anything below 24 would be essentially effortless.
A good point of reference may be to see what DCs are used in published modules. In the Curse of Strahd, for example, there are some crypts with 5ft x 3ft x 3inch stone slabs covering them. Removing or replacing these slabs is a DC 15 check (pg 85). There is a crypt with a large slab (pg. 93) which is 8ft x 6ft (depth is not listed, I would assume again around 3 inch). This one is a DC 20. Yet another tomb (also pg 93) is guarded by a portcullis (heavy metal gate) which is a DC 25 to lift. I cannot find any strength checks in the book with a DC higher than 25.
On page 33, the module says this about doors in the region:
"Doors. A wooden door can be forced open with a successful DC 10 Strength check, or DC 15 if the door is barred or reinforced in some other manner. Increase the DC by 5 if the door is made of stone, or by 10 if it is made of iron. Decrease the DC by 5 if the door is made of glass or amber, or if the door is weakened in some manner (such as by rot or corrosion). ... A typical padlock can be broken by smashing it with a bludgeoning or slashing weapon and succeeding on a DC 20 Strength check."
The rules for jumping (PHB pg. 182) might also help correlate the strength store to real world terms.
Long Jump. When you make a long jump, you cover a number of feet up to your Strength score if you move at least 10 feet on foot immediately before the jump. When you make a standing long jump, you can leap only half that distance.
...
High Jump. When you make a high jump, you leap into the air a number of feet equal to 3 + you Strength modifier (minimum of 0 feet) if you move at least 10 feet on foot immediately before the jump. When you make a standing high jump, you can jump only half that distance.
For a frame of reference, the Olympic record for men's long jump is 29.2ft (8.9m) and women's is 24.3ft (7.4m). Of course, it's not a perfect analogy, as Olympic long jumpers have trained specifically to be good at this and your character is supposedly just good at this from pure strength built up over the years spent killing monsters. It's also important to remember that D&D is not intended to be 100% realistic, so the constraints of the game may not, and need not, always match up perfectly with real life.
