It's called contrastive focus reduplication in a paper on the exact construction by Ghomeshi et al (2004). Natural Language & Linguistic Theory 22: 307–357, 2004.
EDIT
The paper is 52 pages long, the following are extracts taken from the first 8 pages.
CONTRASTIVE FOCUS REDUPLICATION IN ENGLISH
(THE SALAD-SALAD PAPER)
ABSTRACT. This paper presents a phenomenon of colloquial English that
we call Contrastive Reduplication (CR), involving the copying of words
and sometimes phrases as in It’s tuna salad, not SALAD-salad, or Do
you LIKE-HIM-like him? Drawing on a corpus of examples gathered from
natural speech, written texts, and television scripts, we show that CR
restricts the interpretation of the copied element to a ‘real’ or
prototypical reading. (...)
Examples of this construction are
(1)a. I’ll make the tuna salad, and you make the SALAD–salad. ©
b. LIKE-’EM-like-’em? Or, I’d-like-to-get-store-credit-for-that amount
like-’em?2 ©
c. Is he French or FRENCH–French?
d. I’m up, I’m just not UP–up. ©
e. That’s not AUCKLAND–Auckland, is it? ©
f. My car isn’t MINE–mine; it’s my parents’.
g. Oh, we’re not LIVING-TOGETHER–living-together.
(...)
The semantic effect of this construction is to focus the denotation of
the reduplicated element on a more sharply delimited, more specialized,
range. For instance, SALAD–salad in (1a) denotes specifically green salad
as opposed to salads in general, and, in the context in which (1e) was used,
AUCKLAND–Auckland denotes the city in New Zealand as opposed to
other cities that may happen to have this name.
(...)
The use of a word or phrase often leaves open some vagueness, lack of precision, or ambiguity. CR is used as one way to clarify such situations, by specifying a prototypical denotation of the lexical item in contrast to a potentially looser or
more specialized reading. This is clearest when CR is applied to simple
nouns: [(e.g.)]
(3) c. She wasn’t a fancy cow, a Hereford or Black Angus or something,
just a COW–cow. ©
(...)
This characterization is precisely the informal one given by Horn
(1993). He briefly discusses CR (which he labels, following Dray
(1987), the ‘double construction’) stating: “As a rough approximation,
we can say that the reduplicated modifier singles out a member or
subset of the extension of the noun [or verb, or adjective, or
preposition – JG et al.] that represents a true, real, default, or
prototype instance” (p. 48). As already seen in (1), CR can apply to
not only to nouns, but to a range of lexical categories. Regardless of
the lexical category, however, reduplication signals that the “real”
or prototypical meaning of the lexical item is intended:
(4)a. Are you LEAVING–leaving? [i.e., are you “really” leaving (for
good), or are you just stepping out for a minute]
b. A: Are you nervous?
B: Yeah, but, you know, not NERVOUS–nervous. [i.e., not “really” nervous] ©
(...)
Lawrence Horn (p.c.), in more recent work on CR (which he now calls
‘lexical cloning’), categorizes the semantics of this construction
into four types: (a) prototype meaning (which we have already
discussed), (b) literal meaning, (c) intensified meaning, and
(d) ‘value-added’ meaning. An example of literal meaning appears in (12), where reduplication signals that a literal rather than
euphemistic interpretation of coming in for coffee is intended:
(12) [Dialogue between a married couple, recently separated and
now living apart.]
A: Maybe you’d like to come in and have some coffee?
B: Yeah, I’d like that.
A: Just COFFEE-coffee, no double meanings. ©
