Production Technologies
Mixing Methods: Pervious concrete
often uses a dry-mix sequence to avoid
premature closure of voids. A common
approach (documented in the mid-2000s)
is to dry-mix a small portion of
cement with the aggregate to coat
particles, then add most of the water and
admixtures, followed by the remainder of
cement and water. This staged mixing
helps uniformly distribute paste without
generating excessive slurry. Benefits:
Uniform coating of aggregates with
minimal segregation. Challenges:
Requires controlled procedure; standard
ready-mix drums must avoid overmixing.
Compaction and Vibration: Pervious
concrete is minimally consolidated to
preserve voids. Traditional practice (and
manufacturer guidance) uses roller
screeds or vibratory screeds rather
than heavy troweling. Roller screeds (e.g.
Lura Screed) literally roll over the mix to
strike-off surface without deep
compaction. After striking, a cross-roller
or light vibrating roller is often applied to
settle the surface layer. For
laboratory/precast mixes, a typical
, procedure is light rodding (e.g. 25
tampings per 2″ layer) followed by
brief vibration (5–10 sec). Benefits:
Removes surface high spots, achieves
uniform depth, and closes top voids
without overly densifying the mix.
Challenges: Too much vibration or
rolling will fill voids and defeat purpose;
hence timing and equipment must be
calibrated.
Mold Systems and Prefabrication:
Pervious concrete can be cast in
conventional formwork or specialized
molds. A growing technology is modular
precast panels, manufactured under
controlled conditions. Systems like
STORMCRETE have existed
(commercialized 2010s) as large porous
slabs cured off-site.These panels arrive
ready-for-traffic (fully cured) and include
preset lifting points for easy placement.
Benefits: Consistent quality, faster site
installation, all-weather production.
Challenges: Transportation/handling
large panels; joints between panels must
maintain permeability.
3D Printing (Additive
Manufacturing): An emerging method
(mid-2020s research) is 3D concrete
, printing of porous structures. Recent
studies show that print path patterns
at the filament scale can induce targeted
porosity and permeability. For example,
alternating sine or zigzag toolpaths
produce open, permeable printed
elements. Designers can thus
“customize” graded porosity in a single
print.Benefits: Enables complex
geometries and graded porosity in one
monolithic element. Challenges:
Technology is still experimental; mix
rheology must suit extrusion; structural
strength may be anisotropic.
Batching and Process Improvements:
Innovations include mobile continuous
mixers and on-site dosing systems that
precisely meter cement and admixtures.
Some projects use volumetric mixers to
produce pervious mix on-demand. In
precast plants, dual-shaft mixers or
specialized double-shuffle mixers ensure
uniform paste distribution in low-water
mixes. These modern batch systems
improve consistency over earlier drum
mixers. Benefits: Tighter quality control,
reduced waste. Challenges: Requires
calibration for stiff, low-slump mixes; not
all batching plants are equipped.
Mixing Methods: Pervious concrete
often uses a dry-mix sequence to avoid
premature closure of voids. A common
approach (documented in the mid-2000s)
is to dry-mix a small portion of
cement with the aggregate to coat
particles, then add most of the water and
admixtures, followed by the remainder of
cement and water. This staged mixing
helps uniformly distribute paste without
generating excessive slurry. Benefits:
Uniform coating of aggregates with
minimal segregation. Challenges:
Requires controlled procedure; standard
ready-mix drums must avoid overmixing.
Compaction and Vibration: Pervious
concrete is minimally consolidated to
preserve voids. Traditional practice (and
manufacturer guidance) uses roller
screeds or vibratory screeds rather
than heavy troweling. Roller screeds (e.g.
Lura Screed) literally roll over the mix to
strike-off surface without deep
compaction. After striking, a cross-roller
or light vibrating roller is often applied to
settle the surface layer. For
laboratory/precast mixes, a typical
, procedure is light rodding (e.g. 25
tampings per 2″ layer) followed by
brief vibration (5–10 sec). Benefits:
Removes surface high spots, achieves
uniform depth, and closes top voids
without overly densifying the mix.
Challenges: Too much vibration or
rolling will fill voids and defeat purpose;
hence timing and equipment must be
calibrated.
Mold Systems and Prefabrication:
Pervious concrete can be cast in
conventional formwork or specialized
molds. A growing technology is modular
precast panels, manufactured under
controlled conditions. Systems like
STORMCRETE have existed
(commercialized 2010s) as large porous
slabs cured off-site.These panels arrive
ready-for-traffic (fully cured) and include
preset lifting points for easy placement.
Benefits: Consistent quality, faster site
installation, all-weather production.
Challenges: Transportation/handling
large panels; joints between panels must
maintain permeability.
3D Printing (Additive
Manufacturing): An emerging method
(mid-2020s research) is 3D concrete
, printing of porous structures. Recent
studies show that print path patterns
at the filament scale can induce targeted
porosity and permeability. For example,
alternating sine or zigzag toolpaths
produce open, permeable printed
elements. Designers can thus
“customize” graded porosity in a single
print.Benefits: Enables complex
geometries and graded porosity in one
monolithic element. Challenges:
Technology is still experimental; mix
rheology must suit extrusion; structural
strength may be anisotropic.
Batching and Process Improvements:
Innovations include mobile continuous
mixers and on-site dosing systems that
precisely meter cement and admixtures.
Some projects use volumetric mixers to
produce pervious mix on-demand. In
precast plants, dual-shaft mixers or
specialized double-shuffle mixers ensure
uniform paste distribution in low-water
mixes. These modern batch systems
improve consistency over earlier drum
mixers. Benefits: Tighter quality control,
reduced waste. Challenges: Requires
calibration for stiff, low-slump mixes; not
all batching plants are equipped.
