LIPARI PUMICE

LIPARI PUMICE
Concrete lightened with natural aggregates
Resistant and light !
Certificato N° 7245/02/S

Interest regarding lightweight structural concrete is consistently increasing, especially since it is particularly advantageous in prefabs,
where the possibility of using light structural elements help to solve many problems. The use of lightweight structural concrete
is justified, if the following two fundamental requirements are met:
1) An appropriate resistance is obtained (>= 15 N/mm²)
2) The possibility to reinforce the prefab's elements exists, and that the reinforced and pre-stressed beams tend to experience
problems such as shrinkage, freeze resistance, and deformation.
The possibility to reinforce lightweight concrete requires that there is sufficient adherence with the steel framework to ensure the
transmission of tensile stress, from the steel bars to the concrete without slippage or diminishing the protection against corrosion.
The best results in the research for a lightweight concrete with Lipari pumice aggregate, where the resistance values enter with
the limits required of structural concrete, has been obtained with an opportune dosage of pumice aggregate not containing fine
pumice particles, but substituted with crushed rock fine particles, and the opportune use of additives to better the mechanical
characteristics, the adherence to steel and to limit the amount of shrinkage.
Optimum mix tests
Mix composition kg/m³
E - 350* E a - 350 ** R - 250***
Portland Cement 425 350 350 250
Effective Water 175 135 165
Absorbed Water 64 64
Pumice grain size above 7 mm 260 268
Pumice grain size 3-7 mm 205 212
Sea sand° 129 133
Mountain sand°° 486 502
Gravel 5/15 1.300
Sand 0/2 660
Tiamac Additive 11 (1) 3,40
Stabilmac Additive (2) 35
Total 1.670 1.702,40 2.375
Apparent Density Kg/m3 1.600 1.650 2.350
Compression Resistance
in N/mm2 (kg/cm2 ) 18,64 (190) 22,07 (225) 26,48 (270)
Traction Resistance
in N/mm2 ( Kg/cm2 )
LIGHTWEIGHT STRUCTURAL CONCRETE WITH LIPARI PUMICE AGGREGATE
*E-350: Basic Mix
**Ea: Basic mix combined with superfluid additive and an expansion agent²
***R-250: Ordinary reference concrete UNI 10020-7
° Natural sand originating from detached quarries in sandy hills found close to
marine coastline
°° Crushed rock fine particles
1,80 (18,30) 2,28 (23,20) 2,28 (23,20)

SHRINKAGE TESTS
-Shrinkage exerience - 2 to 270 days, with 4 test samples 10x10x50cm
-Seasoning UNI 627
-Monitoring with AMSLER UNI 6555
Shrinkage
Values
ADHERENCE TESTS Prove di aderenza :
Conditioning factors:
- Adhesion due to cement's adhesive properties
- Friction due to the locking action of the concrete
- Concrete resistance to the cutting forces caused by the irregularity of the steel contact.
- Surface shape of the framework
- Concrete's resistance characteristics
- Concrete's compactions around the rods
- Aggregate resistance under concentrated loads
- Concrete elasticity
Test Methodology :
"Beam Test" UNI CNR 120-71
"Claw" type steel with high elasticity and an improved adherence
Rods with nominal diameters 12mm and 20 mm (2 tests each)
Apparatus used: hydraulic oil epuipment type Mohr-Federhaff
Loads applied with a tolerance of 10kg.
TENSION CHARACTERISTICS TO ADHERENCE IN N / mm² (Kg / cm²)
Mix
E - 350
E a - 350
R - 250
Regulations require that: Tm>T*m=80-1,2 d
Result of the rods used : :
diam.
mm. 12
mm. 20
The values noted satisfy the conditions outlined in the regulation and one can consider the behaviour of the lightweight pumice concrete adherence
to steel as being good.
This result improves when using rods with an inferior diameter, since the concentrated forces decreas the possibility of breaking the aggregate.
The influence of the additives is positive, and hence the adherence tension result values improve.
CONCLUSIONS
The tests carried our show satisfactory behaviour of Lipari pumice concrete as far as shrinkage and adherence is concerned, making it possible
to use it as lightweight structural concrete, within the tests resistance monitored limits.
(taken from "The shrinkage and adherence problems of lightweight concrete produced using pumice aggregate" Prof. Ing. Pasquale Mancuso e
Prof. Ing. Vincenzo Ruisi dell' Ist. di Scienza delle Costruzioni - Facoltà di Ingegneria - Univ. Palermo - Dr. Ing. Nunzio Miraglia.)
OTHER CONSIDERATIONS
E - 350 *
0,40 mm. for 270 days
shifting >
rod diam. mm
mm. 12
mm. 20
mm. 12
mm. 20
mm. 12
mm. 20
65, 6 Kgf/cm 2
T* m
56 Kgf/cm 2
^
E a - 350 **
0,15 mm. for 270 days
R - 250 ***
0,10 for 270 days
0,01 mm 0,1 mm 1,00 mm
Fa Td Fa Td Fa Td 181,48 4,51 305,48 7,65 429,19 10,69
(1850) (46) (3114) (78) (4375) (109)
139,30 3,43 234,26 5,89 290,67 7,26
(1420) (35) (2388) (60) (2963) (74)
226,61 5,69 463,13 11,57 504,92 12,65
(2310) (58) (4721) (118) (5147) (129)
195,71 4,90 313,13 7,65 350,51 8,73
(1995) (50) (3192) (80) (3573) (89)
167,45 4,22 345,70 8,63 443,41 11,08
(1707) (43) (3524) (88) (4520) (113)
205,52 5,10 286,65 7,16 341,29 8,53
(2095) (52) (2922) (73) (3479) (87)
In conclusion, the test results have shown that lightweight pumice concrete have behavioural characteristics that are very similar to artificial aggregates with a comparable resistance.
Hence, where high resistance is not required, this can be usefully applied, improving adherence when used with frameworks with low diameters, (which are widely available), for the
making of structural elements such as beams and reinforced concrete slabs.
It is foreseen that in the future the Italian regulations for concrete with artificial aggregates will also be extended to lightweight concrete with pumice aggregates, securitywise modifying
the current limit levels.
T m
7,65
(78)
5,49
(56)
10,01
(102)
7,16
(73)
7,95
(81)
6,96
(71)
T r
10,69
(109)
7,26
(74)
12,65
(129)
8,73
(89)
11,08
(113)
8,53
(87)

Share Capital € 3.873.427
loc. Porticello
98050 Acquacalda di Lipari (ME)
V.A.T. No. 00071230833
Tel.090 9821126 PBX 3 lines
Fax 090 9821044
Sales Offices:
v. M.Macchi, 26 - 20124 Milano - Italy
Tel. 0266710195
Fax 02 66713062
E-mail: pmxcomm@tin.it
http://www.pumex.it